New insights into comprehensive analysis of magnesium transporter (MGT) gene family in rice (Oryza sativa L.).

Magnesium transporters (MGTs) regulate magnesium absorption, transport, and redistribution in higher plants. To investigate the role of the Oryza sativa MGTs gene family members under salt stress, this study analyzed the protein properties, gene structure, phylogenetic relationship, synteny patterns, expression, and co-expression networks of 23 non-redundant OsMGT. The evolutionary relationship of the OsMGT gene family was fully consistent with their functional domain, and were divided into three main classes based on the conserved domain: MMgT, CorA-like, and NIPA. The α/ß patterns in the protein structures were highly similar in the CorA-like and NIPA members, with the conserved structures in the Mg2+-binding and catalytic regions. The CorA-like clade-related proteins demonstrated the highest numbers of protein channels with Pro, Ser, Lys, Gly, and Tyr, as the critical binding residues. The expression analysis of OsMGT genes in various tissues showed that MGTs' gene family may possess critical functions during rice development. Gene expression analysis of candidate OsMGT using reverse-transcription quantitative real-time PCR (RT-qPCR) found that four OsMGT genes exhibited different expression patterns in salt-sensitive and salt-tolerant rice genotypes. We hypothesize that the OsMGT gene family members may be involved in responses to salt stress. These findings could be useful for further functional investigation of MGTs as well as defining their involvement in abiotic stress studies. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03735-4.

Biochemical and Transcriptional Responses in Cold-Acclimated and Non-Acclimated Contrasting Camelina Biotypes under Freezing Stress.

Cold-acclimated and non-acclimated contrasting Camelina (Camelina sativa L.) biotypes were investigated for changes in stress-associated biomarkers, including antioxidant enzyme activity, lipid peroxidation, protein, and proline content. In addition, a well-known freezing tolerance pathway participant known as C-repeat/DRE-binding factors (CBFs), an inducer of CBF expression (ICE1), and a cold-regulated (COR6.6) genes of the ICE-CBF-COR pathway were studied at the transcriptional level on the doubled-haploid (DH) lines. Freezing stress had significant effects on all studied parameters. The cold-acclimated DH34 (a freezing-tolerant line) showed an overall better performance under freezing stress than non-acclimated plants. The non-cold-acclimated DH08 (a frost-sensitive line) showed the highest electrolyte leakage after freezing stress. The highest activity of antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase) was also detected in non-acclimated plants, whereas the cold-acclimated plants showed lower enzyme activities upon stress treatment. Cold acclimation had a significantly positive effect on the total protein and proline content of stressed plants. The qRT-PCR analysis revealed significant differences in the expression and cold-inducibility of CsCBF1-3, CsICE1, and CsCOR6.6 genes among the samples of different treatments. The highest expression of all CBF genes was recorded in the non-acclimated frost-tolerant biotype after freezing stress. Interestingly a significantly higher expression of COR6.6 was detected in cold-acclimated samples of both frost-sensitive and -tolerant biotypes after freezing stress. The presented results provide more insights into freezing tolerance mechanisms in the Camelina plant from both a biochemical point of view and the expression of the associated genes.

High-density linkage mapping for agronomic and physiological traits of rice (Oryza sativa L.) under reproductive-stage salt stress.

Rice is one of the most important cereals of the world, with a substantial amount of genetic variation, and a staple food for more than half of the world's population. Salinity is the second most important abiotic stress after drought that adversely affects rice production globally. Both the seedling and reproductive stages are extremely sensitive to salinity but tolerant at the reproductive stage which is most crucial, as it translates into grain yield. Therefore, it is more important to identify the underlying factors of tolerance at the reproductive stage as a necessary step towards improving varieties for salinity environments. However, because of the difficulties in phenotyping protocols of salinity tolerance screening at the reproductive stage, only a few studies exist on this aspect. In view of this, a study involving 188 F4 rice lines derived from a cross CSR28 × Sadri along with the parents was carried out for phenotyping using a novel screening approach for the reproductive stage in salinity conditions and genotyping by SNP markers (Infinium Illumina 6K SNP chip) to construct a high-saturation linkage map. Quantitative trait loci analysis in an F4 population for physiological traits (chlorophyll a, chlorophyll b and carotenoid) and agronomic traits (plant height, filled grain number, grain yield and spikelet fertility percentage) led to the identification of 14 QTLs with an LOD range of 2.72-4.46 explaining phenotypic variation of 5.29-24.86% on chromosomes 1, 2, 3, 5, 6, 7 and 8. Tolerant alleles were contributed by both CSR28 and Sadri. The results indicated that both physiological and agronomic traits were involved in salinity tolerance at the reproductive stage and majority of the QTLs identified in this study are reported for the first time.

Genetic analysis of freezing tolerance in camelina [Camelina sativa (L.) Crantz] by diallel cross of winter and spring biotypes.

MAIN CONCLUSION: Camelina biotypes had different responses to freezing stress, which was mainly inherited by additive gene effects and can be reliably used in breeding programs and for a better understanding of freezing tolerance mechanisms in camelina plants. Camelina [Camelina sativa (L.) Crantz] is a frost-tolerant oilseed plant that is cultivated as an autumn crop in semi-arid regions. However, camelina establishment in these areas is limited by low temperatures in winter that results in decreased seed yield. In the present study, genetic basis of freezing tolerance (FT) in spring and winter biotypes of camelina was analyzed at seedling stage using a diallel cross experiment. The parents consisted of two winter doubled haploid (DH) lines with high (DH34 and DH31), two spring lines with medium (DH19 and DH26), and two spring lines with low FT (DH08 and DH91). For this purpose, the parents along with F1 entries were subjected to freezing stress and survival percentage, electrolyte leakage, and lethal temperature for 50% mortality (LT50) of the lines were measured. Results showed that although both additive and non-additive effects of the genes determine the FT, further analyses indicated that it was mainly controlled by the additive effects. Therefore, selection-based methods may be more efficient for improving FT in camelina genotypes. The results of specific combining ability (SCA) and heterosis analysis among various DH lines suggested that more tolerant cultivars of camelina could be developed by targeted crossings. When a tolerant winter line and a susceptible spring line were crossed, their progenies showed a higher FT compared with the progenies of a cross between two susceptible spring lines indicating FT is controlled by additive effects of the genes in camelina plants. These findings provided new insight into the genetic basis of freezing-related traits in camelina and could be used for more sophisticated breeding programs.

Purified sulforaphane from broccoli (Brassica oleracea var. italica) leads to alterations of CDX1 and CDX2 expression and changes in miR-9 and miR-326 levels in human gastric cancer cells.

BACKGROUND: Genetic alterations and epigenetic modifications are two main factors involved in gastric carcinogenesis, progression, and metastasis. Several miRNAs such as miRNA-9 and miRNA-326 may play important role in gastric cancer by targeting the 3'UTR of the caudal type homeobox (CDX) 1 and 2 mRNA respectively. The use of herbal medicines has been widely considered in the treatment of cancers such as gastric cancer. Sulforaphane extracted from broccoli may indirectly prevent cancer through affecting different signaling pathways. The aim of this study was to evaluate the effect of different concentrations of sulforaphane extracted from broccoli sprout (SEBS) on viability, death pattern, and expression alterations of CDX1/2 as well as miRNA-9 and miRNA-326 in normal (HF2FF) and gastric cancer cell lines. METHODS: Two gastric cancer cell lines (AGS and MKN45) and HF2FF normal cell line were cultured and treated with different concentrations (31.25, 62.5, 125, and 250 µg/ml) of the purified sulforaphane. Expression levels of CDX1 and CDX2 as well as miRNA-9 and miRNA-326, and mechanisms leading to cell death were assessed by Taqman real time PCR assay and flow cytometry, respectively. RESULTS: Significant dose-dependent and anti-proliferative effects of the SEBS were observed on AGS and MKN45 cells after 48 h with an IC50 value of about 112 and 125 µg/ml, respectively (P < 0.001). Apoptotic cells were observed in AGS and MKN45 cells but not HF2FF after 48 h of treatment with SEBS. Furthermore, significant changes in expression of CDX1, CDX2, miR-9 and miR-326 in the gastric cancer lines (AGS and MKN45), were observed under different concentrations of SEBS. CONCLUSION: Our present study suggests that the SEBS may influence gastric cancer cell lines at specific doses and change their proliferation rate by altering the expression of CDX1, CDX2, miR-9, and miR-326.

Correction: Ghasemi, M., et al. Increase of Chamazulene and α-Bisabolol Contents of the Essential Oil of German Chamomile (Matricaria chamomilla L.) Using Salicylic Acid Treatments under Normal and Heat Stress Conditions Foods 2016, 5, 56.

The authors wish to make the following corrections to their paper [...].

Increase of Chamazulene and α-Bisabolol Contents of the Essential Oil of German Chamomile (Matricaria chamomilla L.) Using Salicylic Acid Treatments under Normal and Heat Stress Conditions.

The chamazulene and α-(-)-bisabolol contents and quality of the chamomile oil are affected by genetic background and environmental conditions. Salicylic acid (SA), as a signaling molecule, plays a significant role in the plant physiological processes. The aim of this study was to evaluate the chemical profile, quantity, and improve the essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabol using salicylic acid under normal and heat stress conditions by the gas chromatography-mass spectrometry (GC-MS) technique. The factorial experiments were carried out during the 2011-2012 hot season using a randomized complete block design with three replications. The factors include four salicylic acid concentrations (0 (control), 10, 25 and 100 mg·L-1), and three chamomile cultivars (Bushehr, Bona, Bodegold) were sown on two different planting dates under field conditions. Fourteen compounds were identified from the extracted oil of the samples treated with salicylic acid under normal and heat stress conditions. The major identified oil compositions from chamomile cultivars treated with salicylic acid were chamazulene, α-(-)-bisabolol, bisabolone oxide, ß-farnesene, en-yn-dicycloether, and bisabolol oxide A and B. Analysis of variance showed that the simple effects (environmental conditions, cultivar and salicylic acid) and their interaction were significant on all identified compounds, but the environmental conditions had no significant effect on bisabolol oxide A. The greatest amount of chamazulene obtained was 6.66% at the concentration of 10 mg·L-1 SA for the Bona cultivar under heat stress conditions, whereas the highest α-(-)-bisabolol amount attained was 3.41% at the concentration of 100 mg·L-1 SA for the Bona cultivar under normal conditions. The results demonstrated that the application of exogenous salicylic acid increases the quantity and essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabolol under normal and heat stress conditions.

In vitro plant regeneration through anther culture of some Iranian local rice (Oryza sativa L.) cultivars.

In this study, effect of different genotypes, different callus induction and regeneration media were investigated using seven Iranian local rice. Anthers were cultured on N6, Fj and L8 media containing the same hormonal combination 3 mg L(-1) NAA, 0.5 mg L(-1) Kn and 0.5 mg L(-1) 2, 4-D and incubated at 25 +/- 1 degree C in dark for callus induction. All varieties in L8 medium, five varieties in Fj medium and six varieties in N6 medium produced highest percentage of callus. Calli induced in different induction media were transferred to SK 11 and N 19 medium and incubated at 25 +/- 1 degree C in light for plantlet regeneration. Among seven varieties upon transfer to SK 11 medium, highest percentage (40%) of green plants were produced in Hassani and in N 19 medium the highest percentage (15.78) of green plants and albino plants (21.05) were produced in Anbarbo. The finding in the present investigation showed that the successfully emberyogenesis and green plant regeneration in rice anther culture dependent on medium culture components and are affected by the genetic mack-up of the plants.