Quantum modeling simulates nutrient effect of bioplastic polyhydroxyalkanoate (PHA) production in Pseudomonas putida.

Polyhydroxyalkanoates (PHAs) could be used to make sustainable, biodegradable plastics. However, the precise and accurate mechanistic modeling of PHA biosynthesis, especially medium-chain-length PHA (mcl-PHA), for yield improvement remains a challenge to biology. PHA biosynthesis is typically triggered by nitrogen limitation and tends to peak at an optimal carbon-to-nitrogen (C/N) ratio. Specifically, simulation of the underlying dynamic regulation mechanisms for PHA bioprocess is a bottleneck owing to surfeit model complexity and current modeling philosophies for uncertainty. To address this issue, we proposed a quantum-like decision-making model to encode gene expression and regulation events as hidden layers by the general transformation of a density matrix, which uses the interference of probability amplitudes to provide an empirical-level description for PHA biosynthesis. We implemented our framework modeling the biosynthesis of mcl-PHA in Pseudomonas putida with respect to external C/N ratios, showing its optimization production at maximum PHA production of 13.81% cell dry mass (CDM) at the C/N ratio of 40:1. The results also suggest the degree of P. putida's preference in channeling carbon towards PHA production as part of the bacterium's adaptative behavior to nutrient stress using quantum formalism. Generic parameters (kD, kN and theta θ) obtained based on such quantum formulation, representing P. putida's PHA biosynthesis with respect to external C/N ratios, was discussed. This work offers a new perspective on the use of quantum theory for PHA production, demonstrating its application potential for other bioprocesses.

A GFP splicing reporter in a coilin mutant background reveals links between alternative splicing, siRNAs, and coilin function in Arabidopsis thaliana.

Coilin is a scaffold protein essential for the structure of Cajal bodies, which are nucleolar-associated, nonmembranous organelles that coordinate the assembly of nuclear ribonucleoproteins (RNPs) including spliceosomal snRNPs. To study coilin function in plants, we conducted a genetic suppressor screen using a coilin (coi1) mutant in Arabidopsis thaliana and performed an immunoprecipitation-mass spectrometry analysis on coilin protein. The coi1 mutations modify alternative splicing of a GFP reporter gene, resulting in a hyper-GFP phenotype in young coi1 seedlings relative to the intermediate wild-type level. As shown here, this hyper-GFP phenotype is extinguished in older coi1 seedlings by posttranscriptional gene silencing triggered by siRNAs derived from aberrant splice variants of GFP pre-mRNA. In the coi1 suppressor screen, we identified suppressor mutations in WRAP53, a putative coilin-interacting protein; SMU2, a predicted splicing factor; and ZCH1, an incompletely characterized zinc finger protein. These suppressor mutations return the hyper-GFP fluorescence of young coi1 seedlings to the intermediate wild-type level. Additionally, coi1 zch1 mutants display more extensive GFP silencing and elevated levels of GFP siRNAs, suggesting the involvement of wild-type ZCH1 in siRNA biogenesis or stability. The immunoprecipitation-mass spectrometry analysis reinforced the roles of coilin in pre-mRNA splicing, nucleolar chromatin structure, and rRNA processing. The participation of coilin in these processes, at least some of which incorporate small RNAs, supports the hypothesis that coilin provides a chaperone for small RNA trafficking. Our study demonstrates the usefulness of the GFP splicing reporter for investigating alternative splicing, ribosome biogenesis, and siRNA-mediated silencing in the context of coilin function.

Hydrogen peroxide regulates the Osa-miR156-OsSPL2/OsTIFY11b module in rice.

Field-grown rice (Oryza sativa L.), when exposed to various environmental stresses, produces high amounts of reactive oxygen species, such as H2 O2 . MicroRNAs (miRNAs) play crucial roles in plant stress responses. This study characterized the functions of H2 O2 -regulated miRNAs in rice. Small RNA deep sequencing revealed that miR156 levels decreased following H2 O2 treatment. Searches of the rice transcriptome and degradome databases indicated that OsSPL2 and OsTIFY11b are miR156-target genes. Interactions between miR156 and OsSPL2 and OsTIFY11b were confirmed using transient expression assays through agroinfiltration. In addition, the levels of OsSPL2 and OsTIFY11b transcripts were lower in transgenic rice plants overexpressing miR156 than in wild-type plants. The OsSPL2-GFP and OsTIFY11b-GFP proteins were localized to the nucleus. Yeast two-hybrid and bimolecular fluorescence complementation assays indicated interactions between OsSPL2 and OsTIFY11b. Furthermore, OsTIFY11b interacted with OsMYC2 to regulate the expression of OsRBBI3-3, which encodes a proteinase inhibitor. The results suggested that H2 O2 accumulation in rice suppresses the expression of miR156, and induces the expression of its target genes, OsSPL2 and OsTIFY11b, whose proteins interact in the nucleus to regulate the expression of OsRBBI3-3, which is involved in plant defense.

MTHFR Knockdown Assists Cell Defense against Folate Depletion Induced Chromosome Segregation and Uracil Misincorporation in DNA.

Folate depletion causes chromosomal instability by increasing DNA strand breakage, uracil misincorporation, and defective repair. Folate mediated one-carbon metabolism has been suggested to play a key role in the carcinogenesis and progression of hepatocellular carcinoma (HCC) through influencing DNA integrity. Methylenetetrahydrofolate reductase (MTHFR) is the enzyme catalyzing the irreversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate that can control folate cofactor distributions and modulate the partitioning of intracellular one-carbon moieties. The association between MTHFR polymorphisms and HCC risk is inconsistent and remains controversial in populational studies. We aimed to establish an in vitro cell model of liver origin to elucidate the interactions between MTHFR function, folate status, and chromosome stability. In the present study, we (1) examined MTHFR expression in HCC patients; (2) established cell models of liver origin with stabilized inhibition of MTHFR using small hairpin RNA delivered by a lentiviral vector, and (3) investigated the impacts of reduced MTHFR and folate status on cell cycle, methyl group homeostasis, nucleotide biosynthesis, and DNA stability, all of which are pathways involved in DNA integrity and repair and are critical in human tumorigenesis. By analyzing the TCGA/GTEx datasets available within GEPIA2, we discovered that HCC cancer patients with higher MTHFR had a worse survival rate. The shRNA of MTHFR (shMTHFR) resulted in decreased MTHFR gene expression, MTHFR protein, and enzymatic activity in human hepatoma cell HepG2. shMTHFR tended to decrease intracellular S-adenosylmethionine (SAM) contents but folate depletion similarly decreased SAM in wildtype (WT), negative control (Neg), and shMTHFR cells, indicating that in cells of liver origin, shMTHFR does not exacerbate the methyl group supply in folate depletion. shMTHFR caused cell accumulations in the G2/M, and cell population in the G2/M was inversely correlated with MTHFR gene level (r = -0.81, p < 0.0001), MTHFR protein expression (r = -0.8; p = 0.01), and MTHFR enzyme activity (r = -0.842; p = 0.005). Folate depletion resulted in G2/M cell cycle arrest in WT and Neg but not in shMTHFR cells, indicating that shMTHFR does not exacerbate folate depletion-induced G2/M cell cycle arrest. In addition, shMTHFR promoted the expression and translocation of nuclei thymidine synthetic enzyme complex SHMT1/DHFR/TYMS and assisted folate-dependent de novo nucleotide biosynthesis under folate restriction. Finally, shMTHFR promoted nuclear MLH1/p53 expression under folate deficiency and further reduced micronuclei formation and DNA uracil misincorporation under folate deficiency. In conclusion, shMTHFR in HepG2 induces cell cycle arrest in G2/M that may promote nucleotide supply and assist cell defense against folate depletion-induced chromosome segregation and uracil misincorporation in the DNA. This study provided insight into the significant impact of MTHFR function on chromosome stability of hepatic tissues. Data from the present study may shed light on the potential regulatory mechanism by which MTHFR modulates the risk for hepatic malignancies.

A Collection of Pre-mRNA Splicing Mutants in Arabidopsis thaliana.

To investigate factors influencing pre-mRNA splicing in plants, we conducted a forward genetic screen using an alternatively-spliced GFP reporter gene in Arabidopsis thaliana This effort generated a collection of sixteen mutants impaired in various splicing-related proteins, many of which had not been recovered in any prior genetic screen or implicated in splicing in plants. The factors are predicted to act at different steps of the spliceosomal cycle, snRNP biogenesis pathway, transcription, and mRNA transport. We have described eleven of the mutants in recent publications. Here we present the final five mutants, which are defective, respectively, in RNA-BINDING PROTEIN 45D (rbp45d), DIGEORGE SYNDROME CRITICAL REGION 14 (dgcr14), CYCLIN-DEPENDENT KINASE G2 (cdkg2), INTERACTS WITH SPT6 (iws1) and CAP BINDING PROTEIN 80 (cbp80). We provide RNA-sequencing data and analyses of differential gene expression and alternative splicing patterns for the cbp80 mutant and for several previously published mutants, including smfa and new alleles of cwc16a, for which such information was not yet available. Sequencing of small RNAs from the cbp80 mutant highlighted the necessity of wild-type CBP80 for processing of microRNA (miRNA) precursors into mature miRNAs. Redundancy tests of paralogs encoding several of the splicing factors revealed their functional non-equivalence in the GFP reporter gene system. We discuss the cumulative findings and their implications for the regulation of pre-mRNA splicing efficiency and alternative splicing in plants. The mutant collection provides a unique resource for further studies on a coherent set of splicing factors and their roles in gene expression, alternative splicing and plant development.

Adsorption Performance for Reactive Blue 221 Dye of ß-Chitosan/Polyamine Functionalized Graphene Oxide Hybrid Adsorbent with High Acid-Alkali Resistance Stability in Different Acid-Alkaline Environments.

A hybrid material obtained by blending ß-chitosan (CS) with triethylenetetramine-functionalized graphene oxide (TFGO) (CSGO), was used as an adsorbent for a reactive dye (C.I. Reactive Blue 221 Dye, RB221), and the adsorption and removal performances of unmodified CS and mix-modified CSGO were investigated and compared systematically at different pH values (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12). The adsorption capacities of CS and CSGO were 45.5 and 56.1 mg/g, respectively, at a pH of 2 and 5.4 and 37.2 mg/g, respectively, at a pH of 12. This indicates that TFGO was successfully introduced into CSGO, enabling π-π interactions and electrostatic attraction with the dye molecules. Additionally, benzene ring-shaped GO exhibited a high surface chemical stability, which was conducive to maintaining the stability of the acid and alkali resistance of the CSGO adsorbent. The RB221 adsorption performance of CS and CSGO at acidic condition (pH 3) and alkaline condition (pH 12) and different temperatures was investigated by calculating the adsorption kinetics and isotherms of adsorbents. Overall, the adsorption efficiency of CSGO was superior to that of CS; thus, CSGO is promising for the treatment of dye effluents in a wide pH range.

MTHFR C677T polymorphism increases MTX sensitivity via the inhibition of S-adenosylmethionine and de novo purine synthesis.

Objective: Currently, no guidelines are established for pharmacogenomic testing involving folate metabolic genes in long-term disease-modifying antirheumatic drugs' (DMARD) therapies. We carefully investigated how common genetic variations in methylenetetrahydrofolate reductase (MTHFR) influence cellular metabolic kinetics in response to methotrexate (MTX). Designs: Two distinct cell models: HepG2 with stabilized MTHFR inhibition using shRNA delivered by a Lentiviral vector; and Epstein-Barr virus transformed human lymphoblasts expressing MTHFR polymorphic allele 677C and 677T were used. Disease activity and DMARD use were compared between MTHFR-677CC, CT and TT rheumatoid arthritis (RA) patients in a cross-sectional study (n=120). Results: Compared with MTHFR-CC, MTHFR-TT carriers had lower mean weakly MTX dose (9.8 ± 3.3 compared with 12.1 ± 3.5, P<0.05). More MTHFR-TT carriers (8/11, 73%) reported MTX-related side effects compared with MTHFR-677CC (32/57, 56%) and MTHFR-677CT (30/51, 59%). No genotypic difference was found in other DMARDs. At the same dose of MTX, lymphoblasts were more sensitive in cell survival, protein and thymidine syntheses whereas HepG2 models were more susceptible to the inhibition of S-adenosylmethionine (adoMet) synthesis. MTHFR-C677T altered protein turnover and folate mediated 1-carbon metabolic fluxes in lymphoblasts with and without MTX. MTHFR function significantly affected transmethylation fluxes and adoMet homeostasis but not nucleotide biosyntheses in MTX-treated HepG2 cell-lines. Conclusion: Combining cell models, kinetic studies, and genetic tests in humans, the present study gives insight on how MTHFR effects hepatic transmethylation homeostasis during MTX therapy. We provide platforms that help predict the genetic impact on antifolate drugs, and further delineate tissue-specific target pathway in DMARD therapies. We suggest that genetic factors should be taken into account in clinical practice.

Isothermal Adsorption Properties for the Adsorption and Removal of Reactive Blue 221 Dye from Aqueous Solutions by Cross-Linked ß-Chitosan Glycan as Acid-Resistant Adsorbent.

Dye effluent causes serious pollution and damage to the environment and needs a series of treatments before it can be discharged. Among the numerous effluent treatment methods, adsorption is the simplest and does not cause secondary pollution. Bio-adsorbents are especially advantageous in the treatment of low-concentration dye effluent. In this study, the adsorption and removal capacities of unmodified α- and ß-chitosan and modified ß-chitosan (ß-chitosan cross-linked with triethylenetetramine, BCCT) on C.I. Reactive Blue 221 (RB221) dye were compared. The experiments were performed on the adsorption of the RB221 dye by unmodified α- and ß-chitosan and cross-linkage⁻modified BCCT at different temperatures and for different durations, which are presented along with the relevant adsorption kinetics calculations. According to the results, as the temperature increased from 303 to 333 K, the initial adsorption rates of the adsorbents, α-chitosan, ß-chitosan, and BCCT, for the RB221 dye, changed from 1.01 × 10², 4.74 × 10², and 1.48 × 106 mg/g min to 5.98 × 104, 4.23 × 108, and 1.52 × 1013 mg/g min, respectively. BCCT thus showed the best adsorption for the dye at all temperatures from the Elovich model. These results confirmed the successful introduction of a polyaminated and cross-linked extended structure as a modification for the BCCT adsorbent, which makes it resistant to acid hydrolysis and gives it the functional amine group for dye adsorption, thereby promoting the ability of BCCT to adsorb dyes under strongly acidic conditions. The compound synthesized in this study is expected to be a good choice in the future for purifying strongly acidic effluent containing anionic organic dyes.

Identification of Coilin Mutants in a Screen for Enhanced Expression of an Alternatively Spliced GFP Reporter Gene in Arabidopsis thaliana.

Coilin is a marker protein for subnuclear organelles known as Cajal bodies, which are sites of various RNA metabolic processes including the biogenesis of spliceosomal small nuclear ribonucleoprotein particles. Through self-associations and interactions with other proteins and RNA, coilin provides a structural scaffold for Cajal body formation. However, despite a conspicuous presence in Cajal bodies, most coilin is dispersed in the nucleoplasm and expressed in cell types that lack these organelles. The molecular function of coilin, particularly of the substantial nucleoplasmic fraction, remains uncertain. We identified coilin loss-of-function mutations in a genetic screen for mutants showing either reduced or enhanced expression of an alternatively spliced GFP reporter gene in Arabidopsis thaliana The coilin mutants feature enhanced GFP fluorescence and diminished Cajal bodies compared with wild-type plants. The amount of GFP protein is several-fold higher in the coilin mutants owing to elevated GFP transcript levels and more efficient splicing to produce a translatable GFP mRNA. Genome-wide RNA-sequencing data from two distinct coilin mutants revealed a small, shared subset of differentially expressed genes, many encoding stress-related proteins, and, unexpectedly, a trend toward increased splicing efficiency. These results suggest that coilin attenuates splicing and modulates transcription of a select group of genes. The transcriptional and splicing changes observed in coilin mutants are not accompanied by gross phenotypic abnormalities or dramatically altered stress responses, supporting a role for coilin in fine tuning gene expression. Our GFP reporter gene provides a sensitive monitor of coilin activity that will facilitate further investigations into the functions of this enigmatic protein.

Regulation of Folate-Mediated One-Carbon Metabolism by Glycine N-Methyltransferase (GNMT) and Methylenetetrahydrofolate Reductase (MTHFR).

Folate-mediated one-carbon metabolism is an important therapeutic target of human diseases. We extensively investigated how gene-nutrient interactions may modulate human cancer risk in 2 major folate metabolic genes, MTHFR and GNMT. The biochemical impacts of MTHFR and GNMT on methyl group supply, global DNA methylation, nucleotide biosynthesis, DNA damage, and partitioning of the folate dependent 1-carbon group were carefully studied. The distinct model systems used included: EB virus-transformed lymphoblasts expressing human MTHFR polymorphic genotypes; liver-derived GNMT-null cell-lines with and without GNMT overexpression; and HepG2 cells with stabilized inhibition of MTHFR using shRNA, GNMT wildtype, heterozygotous (GNMT(het)) and knockout (GNMT(nul)) mice. We discovered that the MTHFR TT genotype significantly reduces folate-dependent remethylation under folate restriction, but it assists purine synthesis when folate is adequate. The advantage of de novo purine synthesis found in the MTHFR TT genotype may account for the protective effect of MTHFR in human hematological malignancies. GNMT affects transmethylation kinetics and S-adenosylmethionine (adoMet) synthesis, and facilitates the conservation of methyl groups by limiting homocysteine remethylation fluxes. Restoring GNMT assists methylfolate-dependent reactions and ameliorates the consequences of folate depletion. GNMT expression in vivo improves folate retention and bioavailability in the liver. Loss of GNMT impairs nucleotide biosynthesis. Over-expression of GNMT enhances nucleotide biosynthesis and improves DNA integrity by reducing uracil misincorporation in DNA both in vitro and in vivo. The systematic series of studies gives new insights into the underlying mechanisms by which MTHFR and GNMT may participate in human tumor prevention.

MicroRNA-mediated regulation of gene expression in the response of rice plants to fungal elicitors.

MicroRNAs (miRNAs) are small non-coding RNAs that have important regulatory functions in plant growth, development, and response to abiotic stress. Increasing evidence also supports that plant miRNAs contribute to immune responses to pathogens. Here, we used deep sequencing of small RNA libraries for global identification of rice miRNAs that are regulated by fungal elicitors. We also describe 9 previously uncharacterized miRNAs in rice. Combined small RNA and degradome analyses revealed regulatory networks enriched in elicitor-regulated miRNAs supported by the identification of their corresponding target genes. Specifically, we identified an important number of miRNA/target gene pairs involved in small RNA pathways, including miRNA, heterochromatic and trans-acting siRNA pathways. We present evidence for miRNA/target gene pairs implicated in hormone signaling and cross-talk among hormone pathways having great potential in regulating rice immunity. Furthermore, we describe miRNA-mediated regulation of Conserved-Peptide upstream Open Reading Frame (CPuORF)-containing genes in rice, which suggests the existence of a novel regulatory network that integrates miRNA and CPuORF functions in plants. The knowledge gained in this study will help in understanding the underlying regulatory mechanisms of miRNAs in rice immunity and develop appropriate strategies for rice protection.

Beyond cleaved small RNA targets: unraveling the complexity of plant RNA degradome data.

BACKGROUND: Degradation is essential for RNA maturation, turnover, and quality control. RNA degradome sequencing that integrates a modified 5'-rapid amplification of cDNA ends protocol with next-generation sequencing technologies is a high-throughput approach for profiling the 5'-end of uncapped RNA fragments on a genome-wide scale. The primary application of degradome sequencing has been to identify the truncated transcripts that result from endonucleolytic cleavage guided by microRNAs or small interfering RNAs. As many pathways are involved in RNA degradation, degradome data should contain other RNA species besides the cleavage remnants of small RNA targets. Nevertheless, no systematic approaches have been established to explore the hidden complexity of plant degradome. RESULTS: Through analyzing Arabidopsis and rice RNA degradome data, we recovered 11 short motifs adjacent to predominant and abundant uncapped 5'-ends. Uncapped ends associated with several of these short motifs were more prevalent than those targeted by most miRNA families especially in the 3' untranslated region of transcripts. Through genome-wide analysis, five motifs showed preferential accumulation of uncapped 5'-ends at the same position in Arabidopsis and rice. Moreover, the association of uncapped 5'-ends with a CA-repeat motif and a motif recognized by Pumilio/Fem-3 mRNA binding factor (PUF) proteins was also found in non-plant species, suggesting that common mechanisms are present across species. Based on these motifs, potential sources of RNA ends that constitute degradome data were proposed and further examined. The 5'-end of small nucleolar RNAs could be precisely captured by degradome sequencing. Position-specific enrichment of uncapped 5'-ends was seen upstream of motifs recognized by several RNA binding proteins especially for the binding site of PUF proteins. False uncapped 5'-ends produced from capped transcripts through non-specific PCR amplification were common artifacts among degradome datasets. CONCLUSIONS: The complexity of plant RNA degradome data revealed in this study may contribute to the alternative applications of degradome in RNA research.

Interaction of small RNA-8105 and the intron of IbMYB1 RNA regulates IbMYB1 family genes through secondary siRNAs and DNA methylation after wounding.

Small RNAs (sRNAs) play important roles in plants under stress conditions. However, limited research has been performed on the sRNAs involved in plant wound responses. In the present study, a novel wounding-induced sRNA, sRNA8105, was identified in sweet potato (Ipomoea batatas cv. Tainung 57) using microarray analysis. It was found that expression of sRNA8105 increased after mechanical wounding. Furthermore, Dicer-like 1 (DCL1) is required for the sRNA8105 precursor (pre-sRNA8105) to generate 22 and 24 nt mature sRNA8105. sRNA8105 targeted the first intron of IbMYB1 (MYB domain protein 1) before RNA splicing, and mediated RNA cleavage and DNA methylation of IbMYB1. The interaction between sRNA8105 and IbMYB1 was confirmed by cleavage site mapping, agro-infiltration analyses, and use of a transgenic sweet potato over-expressing pre-sRNA8105 gene. Induction of IbMYB1-siRNA was observed in the wild-type upon wounding and in transgenic sweet potato over-expressing pre-sRNA8105 gene without wounding, resulting in decreased expression of the whole IbMYB1 gene family, i.e. IbMYB1 and the IbMYB2 genes, and thus directing metabolic flux toward biosynthesis of lignin in the phenylpropanoid pathway. In conclusion, sRNA8105 induced by wounding binds to the first intron of IbMYB1 RNA to methylate IbMYB1, cleave IbMYB1 RNA, and trigger production of secondary siRNAs, further repressing the expression of the IbMYB1 family genes and regulating the phenylpropanoid pathway.

Functional studies of soybean (Glycine max L.) seed LEA proteins GmPM6, GmPM11, and GmPM30 by CD and FTIR spectroscopy.

The protein and mRNA levels of late embryogenesis abundant (LEA) genes may be linked to osmotic stresses. Here, we characterized three soybean hydrophilic LEA proteins--GmPM11 (LEA I), GmPM6 (LEA II), and GmPM30 (LEA III)--by circular dichroism and Fourier transform infrared spectroscopy. Structural analysis revealed that the LEA proteins adopted high amounts of disordered conformations in solution and underwent conformational changes with hydrophobicity and desiccation induction. Macromolecular interaction studies revealed that the GmPM proteins interact with non-reducing sugars and phospholipids. GmPM6 and GmPM30 but not GmPM11 could prevent beta-aggregation of poly-L-lysine after slow drying. We discuss the possible functions of hydrophilic LEA proteins in maturing seeds.

OsLEA1a, a new Em-like protein of cereal plants.

Proteins abundant in seeds during the late stages of development, late embryogenesis abundant (LEA) proteins, are associated with desiccation tolerance. More than 100 of the group I LEA genes, also termed Em genes, have been identified from plants, bacteria and animals. The wide distribution indicates the functional importance of these genes. In the present study, we characterized a novel Em-like gene, OsLEA1a of rice (Oryza sativa). The encoded OsLEA1a protein has an N-terminal sequence similar to that of other plant Em proteins but lacks a 20-mer motif that is the most significant feature of typical Em proteins. The location of the sole intron indicates that the second exon of OsLEA1a is the mutated product of a typical Em gene. Transcriptome analysis revealed OsLEA1a mainly expressed in embryos, with no or only a few transcripts in osmotic stress-treated vegetative tissues. Structural analysis revealed that the OsLEA1a protein adopts high amounts of disordered conformations in solution and undergoes desiccation-induced conformational changes. Macromolecular interaction studies revealed that OsLEA1a protein interacts with non-reducing sugars and phospholipids but not poly-l-lysine. Thus, although the OsLEA1a protein lost its 20-mer motif, it is still involved in the formation of bioglasses with non-reducing sugars or plasma membrane. However, the protein does not function as a chaperone as do other groups of hydrophilic LEA proteins. The orthologs of the OsLEA1a gene had been identified from various grasses but not in dicot plants. Genetic analysis indicated that rice OsLEA1a locates at a 193 kb segment in chromosome 1 and is conserved in several published cereal genomes. Thus, the ancestor of Em-like genes might have evolved after the divergence of monocot plants.