Genome-wide analysis of the Tritipyrum NAC gene family and the response of TtNAC477 in salt tolerance.

NAC transcription factors are widely distributed in the plant kingdom and play an important role in the response to various abiotic stresses in plant species. Tritipyrum, an octoploid derived from hybridization of Triticum aestivum (AABBDD) and Thinopyrum elongatum (EE), is an important genetic resource for integrating the desirable traits of Th. elongatum into wheat. In this study, we investigated the tissue distribution and expression of Tritipyrum NAC genes in the whole genomes of T. aestivum and Th. elongatum after obtaining their complete genome sequences. Based on phylogenetic relationships, conserved motifs, gene synthesis, evolutionary analysis, and expression patterns, we identified and characterized 732 Tritipyrum NAC genes. These genes were divided into six main groups (A, B, C, D, E, and G) based on phylogenetic relationships and evolutionary studies, with members of these groups sharing the same motif composition. The 732 TtNAC genes are widely distributed across 28 chromosomes and include 110 duplicated genes. Gene synthesis analysis indicated that the NAC gene family may have a common ancestor. Transcriptome data and quantitative polymerase chain reaction (qPCR) expression profiles showed 68 TtNAC genes to be highly expressed in response to various salt stress and recovery treatments. Tel3E01T644900 (TtNAC477) was particularly sensitive to salt stress and belongs to the same clade as the salt tolerance genes ANAC019 and ANAC055 in Arabidopsis. Pearson correlation analysis identified 751 genes that correlated positively with expression of TtNAC477, and these genes are enriched in metabolic activities, cellular processes, stimulus responses, and biological regulation. TtNAC477 was found to be highly expressed in roots, stems, and leaves in response to salt stress, as confirmed by real-time PCR. These findings suggest that TtNAC477 is associated with salt tolerance in plants and might serve as a valuable exogenous gene for enhancing salt tolerance in wheat.

Genome-wide analysis of the AP2/ERF gene family in Tritipyrum and the response of TtERF_B2-50 in salt-tolerance.

The AP2/ERF transcription factor is widely distributed across the plant kingdom and plays a crucial role in various abiotic stress responses in plants. Tritipyrum, an octoploid resulting from an intergeneric cross between Triticum aestivum (AABBDD) and Thinopyrum elongatum (EE), is a valuable source of germplasm for incorporating superior traits of Th. elongatum into T. aestivum. With the recent availability of whole -genome sequences for T. aestivum and Th. elongatum, we explored the organization and expression profiling of Tritipyrum AP2/ERF genes across the entire genome. Our investigation identified 543 Tritipyrum AP2/ERF genes, which evolutionary analysis categorized into four major groups (AP2, DREB, ERF, and RAV), whose members share a conserved motif composition. These 543 TtAP2/ERF genes were distributed throughout 28 chromosomes, with 132 duplications. Synteny analysis suggests that the AP2/ERF gene family may have a common ancestor. Transcriptome data and Real-Time PCR expression profiles revealed 43 TtAP2/ERF genes with high expression levels in response to various salt stressors and recovery regimens. Tel2E01T236300 (TtERF_B2-50) was particularly salt stress-sensitive and evolutionarily related to the salt-tolerant gene AtERF7 in A. thaliana. Pearson correlation analysis identified 689 genes positively correlated (R > 0.9) with TtERF_B2-50 expression, enriched in metabolic activities, cellular processes, stimulus response, and biological regulation. Real-time PCR showed that TtERF_B2-50 was highly expressed in roots, stems, and leaves under salt stress. These findings suggest that TtERF_B2-50 may be associated with salt stress tolerance and may serve as a valuable foreign gene for enhancing salt tolerance in wheat.

Identification of a New Pathogenic fungi Causing Sorghum Leaf Spot Disease and Its Management Using Natural Product and Microorganisms.

Sorghum bicolor is cultivated worldwide. Leaf spot of sorghum, which leads to leaf lesions and yield reduction, is a prevalent and serious disease in Guizhou Province, southwest China. In August 2021, new leaf spot symptoms were observed on sorghum leaves. In this study, traditional methods and modern molecular biology techniques were used to isolate and identify the pathogen. Sorghum inoculated with the isolate GY1021 resulted in reddish brown lesion that similar to symptoms observed in the field: the original isolate inoculated was reisolated and Koch's postulates were fulfilled. Based on morphological features and phylogenetic analysis of the internal transcribed spacer (ITS) combined sequence with ß-tubulin (TUB2) and translation elongation factor 1-α (TEF-1α) genes, the isolate was identified as Fusarium thapsinum (Strain accession: GY 1021; GenBank Accession: ITS (ON882046), TEF-1α (OP096445), and ß-TUB (OP096446)). Then, we studied the bioactivity of various natural products and microorganisms against F. thapsinum using the dual culture experiment. Carvacrol, 2-allylphenol, honokiol, and cinnamaldehyde showed excellent antifungal activity, with EC50 values of 24.19, 7.18, 46.18, and 52.81 µg/mL, respectively. The bioactivity of six antagonistic bacteria was measured using a dual culture experiment and the mycelial growth rate method. Paenibacillus polymyxa, Bacillus amyloliquefaciens and Bacillus velezensis displayed significant antifungal effects against F. thapsinum. This study provides a theoretical basis for the green control of leaf spot of sorghum.

GWAS of grain color and tannin content in Chinese sorghum based on whole-genome sequencing.

KEY MESSAGE: Seventy-three QTL related to grain color and tannin content were identified in Chinese sorghum accessions, and a new recessive allelic variant of TAN2 gene was discovered. Sorghum is mainly used for brewing distilled liquors in China. Since grain tannins play an important role in liquor brewing, accurately understanding the relationship between grain color and tannin content can provide basis for selection standards of tannin sorghum. We resequenced a panel of 242 Chinese sorghum accessions and performed population structure and genome-wide association study (GWAS) to identify quantitative trait locus (QTL) affecting pericarp color, testa pigment, and tannin content. Phylogenetic analysis, principal component analysis (PCA), and admixture model were used to infer population structure. Two distinct genetic sub-populations were identified according to their corresponding northern and southern geographic origin. To investigate the genetic basis of natural variation in sorghum grain color, GWAS with 2,760,264 SNPs was conducted in four environments using multiple models (Blink, FarmCPU, GLM, and MLM). Seventy-three QTL were identified to be associated for the color of exocarp, mesocarp, testa, and tannin content on all chromosomes except chromosome 5, of which 47 might be novel QTL. Some important QTL were found to colocalize with orthologous genes in the flavonoid biosynthetic pathway from other plants, including orthologous of Arabidopsis (Arabidopsis thaliana) TT2, TT7, TT12, TT16 and AT5G41220 (GST), as well as orthologous of rice (Oryza sativa) MYB61 and OsbHLH025. Our investigation of the variation in grain color and tannin content in Chinese sorghum germplasm may help guide future sorghum breeding for liquor brewing.

First Report on Colletotrichum fructicola Causing Anthracnose in Chinese Sorghum and Its Management Using Phytochemicals.

Sorghum bicolor is cultivated worldwide. Leaf spots on sorghum, which lead to leaf lesions and impaired growth, are prevalent and severe in Guizhou Province, Southwest China. In August 2021, new leaf spot symptoms were observed on sorghum plants growing in agricultural fields. We used conventional tissue isolation methods and pathogenicity determination tests. Inoculations of sorghum with isolate 022ZW resulted in brown lesions similar to those observed under field conditions. The original inoculated isolates were reisolated and fulfilled Koch's postulates. Based on the morphological character and phylogenetic analyses of the combined sequences of the internal transcribed spacer (ITS) region and the ß-tubulin (TUB2) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes, we identified the isolated fungus as C. fructicola. This paper is the first to report this fungus-causing disease in sorghum leaves. We studied the sensitivity of the pathogen to various phytochemicals. The sensitivity of C. fructicola to seven phytochemicals was measured using the mycelial growth rate method. Honokiol, magnolol, thymol, and carvacrol displayed good antifungal effects, with EC50 (concentration for 50% of the maximal effect) values of 21.70 ± 0.81, 24.19 ± 0.49, 31.97 ± 0.51, and 31.04 ± 0.891 µg/mL, respectively. We tested the control effect of the seven phytochemicals on the anthracnose caused by C. fructicola: honokiol and magnolol displayed good field efficacy. In this study, we expand the host range of C. fructicola, providing a basis for controlling sorghum leaf diseases caused by C. fructicola.

The TaWRKY22-TaCOPT3D Pathway Governs Cadmium Uptake in Wheat.

Cadmium (Cd) is a heavy metal nonessential for plants; this toxic metal accumulation in crops has significant adverse effects on human health. The crosstalk between copper (Cu) and Cd has been reported; however, the molecular mechanisms remain unknown. The present study investigated the function of wheat Cu transporter 3D (TaCOPT3D) in Cd tolerance. The TaCOPT3D transcripts significantly accumulated in wheat roots under Cd stress. Furthermore, TaCOPT3D-overexpressing lines were compared to wildtype (WT) plants to test the role of TaCOPT3D in Cd stress response. Under 20 mM Cd treatment, TaCOPT3D-overexpressing lines exhibited more biomass and lower root, shoot, and grain Cd accumulation than the WT plants. In addition, overexpression of TaCOPT3D decreased the reactive oxygen species (ROS) levels and increased the active antioxidant enzymes under Cd conditions. Moreover, the transcription factor (TF) TaWRKY22, which targeted the TaCOPT3D promoter, was identified in the regulatory pathway of TaCOPT3D under Cd stress. Taken together, these results show that TaCOPT3D plays an important role in regulating plant adaptation to cadmium stress through bound by TaWRKY22. These findings suggest that TaCOPT3D is a potential candidate for decreasing Cd accumulation in wheat through genetic engineering.

Genome-wide identification, phylogenetic analysis, and expression profiles of trihelix transcription factor family genes in quinoa (Chenopodium quinoa Willd.) under abiotic stress conditions.

BACKGROUND: The trihelix family of transcription factors plays essential roles in the growth, development, and abiotic stress response of plants. Although several studies have been performed on the trihelix gene family in several dicots and monocots, this gene family is yet to be studied in Chenopodium quinoa (quinoa). RESULTS: In this study, 47 C. quinoa trihelix (CqTH) genes were in the quinoa genome. Phylogenetic analysis of the CqTH and trihelix genes from Arabidopsis thaliana and Beta vulgaris revealed that the genes were clustered into five subfamilies: SIP1, GTγ, GT1, GT2, and SH4. Additionally, synteny analysis revealed that the CqTH genes were located on 17 chromosomes, with the exception of chromosomes 8 and 11, and 23 pairs of segmental duplication genes were detected. Furthermore, expression patterns of 10 CqTH genes in different plant tissues and at different developmental stages under abiotic stress and phytohormone treatment were examined. Among the 10 genes, CqTH02, CqTH25, CqTH18, CqTH19, CqTH25, CqTH31, and CqTH36, were highly expressed in unripe achenes 21 d after flowering and in mature achenes compared with other plant tissues. Notably, the 10 CqTH genes were upregulated in UV-treated leaves, whereas CqTH36 was consistently upregulated in the leaves under all abiotic stress conditions. CONCLUSIONS: The findings of this study suggest that gene duplication could be a major driver of trihelix gene evolution in quinoa. These findings could serve as a basis for future studies on the roles of CqTH transcription factors and present potential genetic markers for breeding stress-resistant and high-yielding quinoa varieties.

The GzMYB-7D1 gene of Guizimai No.1 wheat is essential for seed anthocyanins accumulation and yield regulation.

Anthocyanins are antioxidants with important benefits for human health. Therefore, they have caught the interest of plant breeding programs. In this study, GzMYB-7D1, the key gene responsible for anthocyanin synthesis regulation in the purple Guizimai No.1 wheat, was transferred into Zhonghua 11 (ZH11) rice. Compared to wild-type ZH11, anthocyanin accumulated in the seeds of GzMYB-7D1 overexpressing lines. Furthermore, anthocyanin content kept increasing in the growing panicle of GzMYB-7D1 overexpressing lines, accumulating mostly in the rice glumes and grains during maturation, along with a concomitant steady decrease in chlorophyll. Genes related to anthocyanin synthesis, including OsPAL4, Os4CL3, OsCHS, OsDFR, OsANS, and Os3GT, exhibited much higher expression in the panicles of GzMYB-7D1 overexpressing lines than in those of wild-type ZH11. Interestingly, the grain yield per plant was significantly improved in GzMYB-7D1 overexpressing lines, as indicated by a higher tiller number per plant and branching of the secondary panicle, together with a significantly higher content of total amino acids. In conclusion, the GzMYB-7D1 gene of Guizimai No.1 wheat is essential for regulating seed anthocyanin levels and grain yield in rice, and could be applied to attain rice varieties with better nutritional value and improved yields.

Selection Signatures in Chinese Sorghum Reveals Its Unique Liquor-Making Properties.

Chinese sorghum (S. bicolor) has been a historically critical ingredient for brewing famous distilled liquors ever since Yuan Dynasty (749 ∼ 652 years BP). Incomplete understanding of the population genetics and domestication history limits its broad applications, especially that the lack of genetics knowledge underlying liquor-brewing properties makes it difficult to establish scientific standards for sorghum breeding. To unravel the domestic history of Chinese sorghum, we re-sequenced 244 Chinese sorghum lines selected from 16 provinces. We found that Chinese sorghums formed three distinct genetic sub-structures, referred as the Northern, the Southern, and the Chishui groups, following an obviously geographic pattern. These sorghum accessions were further characterized in liquor brewing traits and identified selection footprints associated with liquor brewing efficiency. An importantly selective sweep region identified includes several homologous genes involving in grain size, pericarp thickness, and architecture of inflorescence. Our result also demonstrated that pericarp strength rather than grain size determines the ability of the grains to resist repeated cooking during brewing process. New insight into the traits beneficial to the liquor-brewing process provides both a better understanding on Chinese sorghum domestication and a guidance on breeding sorghum as a multiple use crop in China.

Overexpression of TaLAX3-1B alters the stomatal aperture and improves the salt stress resistance of tobacco.

BACKGROUND: Stomata, which play important roles in both optimizing photosynthesis efficiency and adapting to stress, are closely related to IAA and ABA. In plants, the auxin influx carrier LAX3 has been found to play roles in development and stress tolerance. However, the function of LAX3 in stomata and in response to salt stress remains largely unknown. METHODS AND RESULTS: Here, we show that overexpression of wheat TaLAX3-1B in tobacco results in a decrease in stomatal aperture and a relatively closed state of the stomata. In addition, the stomatal movement of the OxTaLAX3-1B lines was less sensitive to ABA than that of the WT. Consistently, compared with the WT, the OxTaLAX3-1B lines showed significantly higher expression of stomate-, IAA- and ABA-related genes and endogenous IAA and ABA contents. Furthermore, compared with the WT, the OxTaLAX3-1B lines exhibited higher proline content, salt stress-related gene expression and ROS antioxidant enzyme activity but lower MDA content and ROS accumulation after salt treatment. CONCLUSIONS: The present results suggest that TaLAX3-1B plays a positive role in regulating stomatal closure and enhancing salt stress tolerance.

Genetic mapping of powdery mildew resistance genes in wheat landrace Guizi 1 via genotyping by sequencing.

BACKGROUND: Wheat (Triticum aestivum L.) powdery mildew (Pm), which caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease worldwide that causes severe yield losses in wheat. Resistant wheat cultivars easily lose their ability to effectively resist newly emerged Bgt strains; therefore, identifying new resistance genes is necessary for breeding resistant cultivars. METHODS AND RESULTS: Guizi 1 (GZ1) is a Chinese wheat cultivar with moderate and stable resistance to Pm. Genetic analysis indicated that the Pm resistance of GZ1 was controlled by a single dominant gene, designated PmGZ1. In total, 110 F2 individual plants and their 2 parents were subjected to genotyping by sequencing (GBS), which yielded 23,134 high-quality single-nucleotide polymorphisms (SNPs). The SNP distributions across the 21 chromosomes ranged from 134 on chromosome 6D to 6288 on chromosome 3B. Chromosome 6A has 1866 SNPs, among which 16 are physically located between positions 307,802,221 and 309,885,836 in an approximate 2.3-cM region; this region also had the greatest SNP density. The average map distance between SNP markers was 0.1 cM. A quantitative trait locus (QTL) with a significant epistatic effect on Pm resistance was mapped to chromosome 6A. The logarithm of odds (LOD) value of PmGZ1 was 34.8, and PmGZ1 was located within the confidence interval marked by chr6a-307802221 and chr6a-309885836. Moreover, 74.7% of the phenotypic variance was explained by PmGZ1. Four candidate genes (which encoded two TaAP2-A and two actin proteins) were annotated maybe as resistance genes. CONCLUSIONS: The present results provide valuable information for wheat genetic improvement, QTL fine mapping, and candidate gene validation.

Expression Analysis Reveals That Sorghum Disease Resistance Protein SbSGT1 Is Regulated by Auxin.

SGT1 (suppressor of the skp1 G2 allele) is an important plant disease resistance-related protein, which plays an important role in plant resistance to pathogens and regulates signal transduction during the process of plant disease resistance. In this study, we analyzed the expression profile of SbSGT1 in sorghum under phytohormones treatment. Quantitative real-time PCR results showed that SbSGT1 was most expressed in sorghum leaves, and could respond to plant hormones such as auxin, abscisic acid, salicylic acid, and brassinolide. Subsequently, we determined the optimal soluble prokaryotic expression conditions for SbSGT1 and purified it using a protein purification system in order to evaluate its potential interactions with plant hormones. Microscale thermophoretic analysis showed that SbSGT1 exhibited significant interactions with indole-3-acetic acid (IAA), with a Kd value of 1.5934. Furthermore, the transient expression of SbSGT1 in Nicotiana benthamiana indicated that treatment with exogenous auxin could inhibit SbSGT1 expression, both at the transcriptional and translational level, demonstrating that there exists an interaction between SbSGT1 and auxin.

Traditional soybean (Glycine max) breeding increases seed yield but reduces yield stability under non-phosphorus supply.

Traditional soybean (Glycine max L.) breeding has improved seed yield in high-input agricultural systems, under high nitrogen (N), phosphorus (P) and potassium (K) supply. The seed yield improvements under non-P supply and the seed protein and mineral content dilution by yield improvement were evaluated in 18 soybean cultivars released from 1995 to 2016 in south-east China. Soybean varieties were grown under rainfed conditions in the field under 0 and 35kgPha-1 in four sites: Dafang and Shiqian in the growing season of 2017 and Dafang and Puding in the 2018 season. The seed yield, seed protein content and nine seed nutrition concentration were examined. Soybean seed yield increased with the year of release at rates of 5.5-6.7gm-2 year-1 under 35kgPha-1 and 3.9-4.8gm-2 year-1 under non-P supply in the four experiments. The increase resulted from increases in the number of filled-pods and total seed number rather than from single seed weight and number of seeds per pod. Seed protein content and seed nutrition concentration has not changed with the year of release under 0 and 35kgPha-1 . Grain yield was positively correlated with the seed Fe concentration. The cultivar superiority of seed yield, seed P, Zn and Ca concentration was negatively correlated with their static stability coefficient. Traditional soybean breeding increased yield under both P and non-P supply, without affecting seed protein content and mineral concentrations. A trade-off between high seed yield and seed P, Zn and Ca concentration and their stability under different environments was shown.

Genome-wide analysis of the Tritipyrum WRKY gene family and the response of TtWRKY256 in salt-tolerance.

Introduction: The transcription factor WRKY is widespread in the plant kingdom and plays a crucial role in diverse abiotic stress responses in plant species. Tritipyrum, an octoploid derived from an intergeneric cross between Triticum aestivum (AABBDD) and Thinopyrum elongatum (EE), is a valuable germplasm resource for introducing superior traits of Th. elongatum into T. aestivum. The recent release of the complete genome sequences of T. aestivum and Th. elongatum enabled us to investigate the organization and expression profiling of Tritipyrum WRKY genes across the entire genome. Results: In this study, 346 WRKY genes, from TtWRKY1 to TtWRKY346, were identified in Tritipyrum. The phylogenetic analysis grouped these genes into three subfamilies (I-III), and members of the same subfamilies shared a conserved motif composition. The 346 TtWRKY genes were dispersed unevenly across 28 chromosomes, with 218 duplicates. Analysis of synteny suggests that the WRKY gene family may have a common ancestor. Expression profiles derived from transcriptome data and qPCR demonstrated that 54 TtWRKY genes exhibited relatively high levels of expression across various salt stresses and recovery treatments. Tel1E01T143800 (TtWRKY256) is extremely sensitive to salt stress and is on the same evolutionary branch as the salt-tolerant A. thaliana genes AtWRKY25 and AtWRKY33. From 'Y1805', the novel AtWRKY25 was cloned. The Pearson correlation analysis identified 181 genes that were positively correlated (R>0.9) with the expression of TtWRKY256, and these genes were mainly enriched in metabolic processes, cellular processes, response to stimulus, biological regulation, and regulation of biological. Subcellular localization and qRT-PCR analysis revealed that TtWRKY256 was located in the nucleus and was highly expressed in roots, stems, and leaves under salt stress. Discussion: The above results suggest that TtWRKY256 may be associated with salt stress tolerance in plants and may be a valuable alien gene for improving salt tolerance in wheat.

Genome-wide identification and expression profile analysis of trihelix transcription factor family genes in response to abiotic stress in sorghum [Sorghum bicolor (L.) Moench].

BACKGROUND: Transcription factors, including trihelix transcription factors, play vital roles in various growth and developmental processes and in abiotic stress responses in plants. The trihelix gene has been systematically studied in some dicots and monocots, including Arabidopsis, tomato, chrysanthemum, soybean, wheat, corn, rice, and buckwheat. However, there are no related studies on sorghum. RESULTS: In this study, a total of 40 sorghum trihelix (SbTH) genes were identified based on the sorghum genome, among which 34 were located in the nucleus, 5 in the chloroplast, 1 (SbTH38) in the cytoplasm, and 1 (SbTH23) in the extracellular membrane. Phylogenetic analysis of the SbTH genes and Arabidopsis and rice trihelix genes indicated that the genes were clustered into seven subfamilies: SIP1, GTγ, GT1, GT2, SH4, GTSb8, and orphan genes. The SbTH genes were located in nine chromosomes and none on chromosome 10. One pair of tandem duplication gene and seven pairs of segmental duplication genes were identified in the SbTH gene family. By qPCR, the expression of 14 SbTH members in different plant tissues and in plants exposed to six abiotic stresses at the seedling stage were quantified. Except for the leaves in which the genes were upregulated after only 2 h exposure to high temperature, the 12 SbTH genes were significantly upregulated in the stems of sorghum seedlings after 24 h under the other abiotic stress conditions. Among the selected genes, SbTH10/37/39 were significantly upregulated, whereas SbTH32 was significantly downregulated under different stress conditions. CONCLUSIONS: In this study, we identified 40 trihelix genes in sorghum and found that gene duplication was the main force driving trihelix gene evolution in sorghum. The findings of our study serve as a basis for further investigation of the functions of SbTH genes and providing candidate genes for stress-resistant sorghum breeding programmes and increasing sorghum yield.

Seed priming with calcium chloride enhances wheat resistance against wheat aphid Schizaphis graminum Rondani.

BACKGROUND: Calcium is an essential macronutrient for plant growth. Although it has been shown that exogenous Ca application can increase plant resistance to abiotic stress, little is known about its potential to enhance plant tolerance to biotic stress. Here, we investigated whether pretreatment of wheat (Triticum aestivum L.) seeds with calcium chloride (CaCl2 ) improves plant resistance against wheat aphid (Schizaphis graminum Rondani). The developmental time, population size, feeding behavior of aphids on plants grown from CaCl2 - and water-pretreated seeds, and plant defense responses to aphid attack were investigated. RESULTS: Seed pretreatment with CaCl2 extended aphid development time and reduced aphid population size and feeding efficiency. In addition, the pretreatment significantly increased the concentration of Ca2+ in wheat leaves, and upregulated expression levels of TaCaM genes and callose synthase genes (TaGSL2, TaGSL8, TaGSL10, TaGSL12, TaGSL19, TaGSL22 and TaGSL23). Callose concentration in the leaves of plants grown from CaCl2 -pretreated seeds increased significantly upon aphid attack. Further, callose deposition was observed mainly in the phloem. CONCLUSION: These results suggest that seed pretreatment with CaCl2 primes the plant response against wheat aphid attack, leading to modulation of callose deposition in the phloem in response to aphid attack. © 2021 Society of Chemical Industry.

Integrated transcriptomic and proteomic analysis of Tritipyrum provides insights into the molecular basis of salt tolerance.

BACKGROUND: Soil salinity is a major environmental stress that restricts crop growth and yield. METHODS: Here, crucial proteins and biological pathways were investigated under salt-stress and recovery conditions in Tritipyrum 'Y1805' using the data-independent acquisition proteomics techniques to explore its salt-tolerance mechanism. RESULTS: In total, 44 and 102 differentially expressed proteins (DEPs) were identified in 'Y1805' under salt-stress and recovery conditions, respectively. A proteome-transcriptome-associated analysis revealed that the expression patterns of 13 and 25 DEPs were the same under salt-stress and recovery conditions, respectively. 'Response to stimulus', 'antioxidant activity', 'carbohydrate metabolism', 'amino acid metabolism', 'signal transduction', 'transport and catabolism' and 'biosynthesis of other secondary metabolites' were present under both conditions in 'Y1805'. In addition, 'energy metabolism' and 'lipid metabolism' were recovery-specific pathways, while 'antioxidant activity', and 'molecular function regulator' under salt-stress conditions, and 'virion' and 'virion part' during recovery, were 'Y1805'-specific compared with the salt-sensitive wheat 'Chinese Spring'. 'Y1805' contained eight specific DEPs related to salt-stress responses. The strong salt tolerance of 'Y1805' could be attributed to the strengthened cell walls, reactive oxygen species scavenging, osmoregulation, phytohormone regulation, transient growth arrest, enhanced respiration, transcriptional regulation and error information processing. These data will facilitate an understanding of the molecular mechanisms of salt tolerance and aid in the breeding of salt-tolerant wheat.

Coix lacryma-jobi chymotrypsin inhibitor displays antifungal activity.

A novel chymotrypsin inhibitor, named ClCI, was purified from coix seed (Coix lacryma-jobi L.) by aqueous two-phase extraction, chymotrypsin-Sepharose 4B affinity chromatography and centrifugal ultrafiltration. ClCI was a 7.9 kDa competitive inhibitor with pI 6.54. The inhibition constants (Ki) for bovine pancreatic chymotrypsin and bacterial subtilisin were 1.27 × 10-10 M and 1.57 × 10-9 M respectively. ClCI had no inhibitory activity against bovine trypsin and porcine elastase. ClCI had wide pH stability and good heat resistance. It can maintain >90% inhibition activity against chymotrypsin at 20-80 °C for 1 h. The primary structure of ClCI was highly similar (57%-92%) to those of several inhibitors belonging to the Gramineae crop potato protease inhibitor- I superfamily and showed the typical sequence motif of the protease inhibitor of the seed storage protein group. ClCI (12.5 mg) inhibited mycelial growth of the phytopathogenic fungi Mycosphaerella melonis, Helminthosporium turcicum, Alternaria solani, Phytophthora capsici, Isariopsis griseola, and Colletotrichum gloeosporioides, and caused 89% inhibition of the proteases from spore germination of plant-pathogenic fungi. The results of the present study indicate that ClCI had biotechnological potential as an alternative agent to combat the important phytopathogenic fungi.

Upregulated structural and regulatory genes involved in anthocyanin biosynthesis for coloration of purple grains during the middle and late grain-filling stages.

Anthocyanin biosynthesis is controlled by structural and regulatory genes. Purple wheat grains accumulate anthocyanin during developmental processes. However, anthocyanin cannot accumulate at the beginning of grain formation. To understand the reason for this phenomenon, we performed observations and analyses of pigments, developmental stages, and the transcriptome of caryopsis in Triticum aestivum L. cv. Guizi 1 (GZ1). In the early grain-filling stage (10 dpa to 20 dpa), anthocyanin accumulated from nearly 0 mg·kg-1 (10 dpa) to 15.39 mg·kg-1 (20 dpa), and the expression levels of structural genes (except GzDFR) and main regulatory genes GzMYB-7D1 and GzMYC-2A1 were low. When the grains developed to the middle (20 dpa to 30 dpa) and late (30 dpa to 40 dpa) grain-filling stages, the anthocyanin content peaked at 197.31 mg·kg-1, and the expression levels of structural and regulatory genes at 25 dpa and 35 dpa were higher than that at 10 dpa. In particular, the expression levels of GzANS, Gz3GT, GzMYB-7D1, and GzMYC-2A1 were upregulated 45.74˜28.54, 765.00˜384.00, 419.00˜574.00, and 5.34˜29.05 times, respectively. Grains were also colored from green to purple. Anthocyanin accumulates in the pericarp and testa and is stored in vacuoles of epidermal and transverse cells. The major compositions are cyanidin and peonidin. These results revealed that the upregulated structural and regulatory genes in the middle and late grain-filling stages may result in the anthocyanin biosynthesis and coloration of grains, which provides new insights into anthocyanin biosynthesis and regulation mechanisms.

Chromosome Pairing in Hybrid Progeny between Triticum aestivum and Elytrigia elongata.

In this study, the intergeneric hybrids F1, F2, BC1F1, BC1F2, and BC2F1 from Elytrigia elongata and Triticum aestivum crosses were produced to study their chromosome pairing behavior. The average E. elongata chromosome configuration of the two F1 hybrids agreed with the theoretical chromosome configuration of 21I+7II, indicating that the genomic constitution of this F1 hybrid was ABDStStEeEbEx. Compared with the BC1F1 generation, the BC2F1 generation showed a rapid decrease in the number of E. elongata chromosomes and the BC1F2 generation showed a more extensive distribution of E. elongata chromosomes. In addition, pairing between wheat and E. elongata chromosomes was detected in each of the wheat-E. elongata hybrid progenies, albeit rarely. Our results demonstrated that genomic in situ hybridization (GISH) using an E. elongata genomic DNA probe offers a reliable approach for characterizing chromosome pairing in wheat and E. elongata hybrid progenies.