Plant Gene最新文献

Due to high cost, limited labour, and longer time required in hybrid development, identifying promising hybrids at an early stage without large-scale yield trials is crucial. Therefore this study estimated heterosis of quality protein maize hybrids for grain yield (GY) and other agronomic traits and investigated relationship of genetic and phenotypic distances (GD, PD) of inbreds with hybrid performance (HP) and mid-and-better parent heterosis (MPH, BPH). Forty-five hybrids generated by half-diallel with 10 inbreds were evaluated for GY and other agronomic traits at three locations. The yield trials were conducted for two years (2017 and 2018 cropping seasons). The GD and PD were 0.45 and 0.40 based on SSR and phenotypic data, respectively, this shows moderate genetic variation existed among inbreds. GY had highest MPH (77.55%) and BPH (53.96%) with hybrid TZEEQI-9 × TZEEQI-16 having highest MPH (382.8%) and BPH (331.7%), across locations. Positive and significant association existed between SSR-GD with HP, MPH and BPH for ear length, kernels/row and 100-seed weight (r = 0.31** to 0.41**), this suggests these traits can be predicted from SSR-based GD of parents. These traits could be used for indirect selection for yield improvement. However, negative correlation was obtained between SSR-GD with HP, MPH and BPH for anthesis and silking (r = −0.29 to −0.03), this indicates the dominance for earliness to flowering and silking than their parental lines. The two distance measures can be used to differentiate between maize inbreds and assigned them to different heterotic groups and Breeders can therefore prioritize crosses with high heterosis and desirable phenotypic traits, saving time, resources, and field space.

PYLs (pyrabactin resistance1/PYR1-like) sense ABA, an essential phytohormone that regulates plant growth and stress responses. PYLs act as the main controllers of ABA stress signaling in plants. In this study, a total of 10 HvPYLs were discovered in the barley genome using an in silico genome search technique. These HvPYLs were then grouped into 3 subfamilies based on a phylogenetic analysis that compared them to the genomes of Arabidopsis, Brachypodium, rice, and maize. These HvPYLs demonstrated conserved motif compositions and identical protein structures across clades. Additionally, this study includes detailed investigations of gene structure variations, chromosomal distributions, cis-regulatory elements, protein-protein interactions, expression profiles in different tissues, and stress responses. We identified various cis-elements in the HvPYL promoter regions related to plant development and stresses indicating their potential roles in development and stress management. Our analysis of the interaction network has identified that HvPYLs can interact with key components of the ABA signaling pathway, demonstrating the critical regulatory functions of HvPYL genes in managing stress and growth in barley. These findings provide a basis for future research aimed at exploring the functions of PYL genes, with the ultimate goal of enhancing stress tolerance in barley and other related species.

Suaeda salsa represents a promising halophyte model for investigating the mechanisms underlying salt tolerance in plants. However, the molecular mechanisms regulating seedling establishment of Suaeda salsa remain unknown. Thus, the current study was conducted to understand the underlying regulatory mechanisms in Suaeda salsa leaves exposed to 0 mM, 200 mM, 400 mM, and 800 mM NaCl using high-throughput RNA sequencing. The number of differentially expressed transcripts substantially increased when the salinity level elevated, suggesting major transcriptional reorganization in response to salinity stress. Importantly, the differentially identified transcripts were mostly salt responsive genes belonging to specific categories like plant hormone signaling, solute transport and nutrient uptake, protein metabolism, and transcriptional regulation. Specifically, higher level of salt changed 339 genes markedly implicated in transcriptional regulation such as MYB, MADS-box, NAC, ERF, WRKY, HB families, as well as genes involved in protein metabolism such as the tyrosine-like protein and ATG members and autophagic cargo receptor protein. This indicated important key players to high salt tolerance. Collectively, our findings revealed the crucial regulatory pathways underlying the salt tolerance of Suaeda salsa through a cascade that includes signal perception and transduction, and transcription factors that regulate the downstream response genes such as those involved in protein metabolism, solute and nutrient transport for salt stress adaptation.

Glycosylated proteins like germin-like proteins (GLPs) are incredibly diverse inside the kingdom Plantae, and mostly GLPs exhibit superoxide dismutase (SOD) function. Identification of catalytic residues is important for understanding the mechanism of enzyme-catalyzed reactions. The increased bioactivity of SOD was observed when OsRGLP1 was over-expressed in tobacco. The purpose of the current work was to identify and characterize the active site of OsRGLP1. Bioinformatics tools were used to predict the three-dimensional structure of OsRGLP1 and the shape of residues implicated in the substrate and metal ion binding. The role of predicted active site residues (E116, H109, H111, and H157) in the structure-function relationship in OsRGLP1 was investigated by site-directed mutagenesis where each residue was substituted with glycine. These amino acids are highly conserved among GLP family and structural data have implicated these residues in substrate binding at the active site. Transient transformation of tobacco plants was performed to further study these loss-of-function mutants. To investigate the impact of the mutation on SOD activity, these transgenic plants were employed as a source of mutant and native proteins for SOD activity assays. The SOD assay results revealed a complete loss of activity in all mutants, supporting the crucial role of these residues for metal ion binding in the enzyme active site.

Three-line hybrid rice system is the most successful and widely practiced method around the world. Hybrid rice breeders have used B × B, A × R and R × R (R = Restorer line, B = Maintainer line, A = CMS line) scheme of parental line improvement frequently and avoided B × R and R × B scheme. As a result, female parents lack the genetic diversity carried by R lines. But B × R and R × B mating have great potential to produce high value parental lines of hybrid rice and overcome the limitation of the previous approach. We have demonstrated a new method for three-line hybrid system to minimize the barrier of crossing in parent selection for developing new elite maintainers and restorers. Parental combinations were selected based on breeding value of the genotypes. Breeding values were estimated based on ancestor, pedigree information and yield data of 74 test genotype to select parents for restorer and maintainer line improvement. This new protocol allows (B × R), (R × B) (R × Elite) and (B × Elite) improvement technique to bring out high yielding diverse B and R lines. This B line will be used for developing new A line in the genetic background of B line. Doubled haploid and RGA i.e. rapid generation advance tools of breeding will save the precious time and reduce breeding cycle length; and large population size will increase selection accuracy. We have predicted the genetic gain in parental line development for four parental cross using the studied 74 genotypes for doubled haploid and rapid generation advance methods. Our objectives were to demonstrate the new breeding approach plus breeding value and positive dominant gene effect-based parent selection strategy. We are hopeful about the new method that hybrid rice breeders across the world will extract benefit utilizing the new methodology of hybrid rice parental line development.

Erysiphe pisi is one among the other causal agents of powdery mildew infection in garden pea. So far, the resistance genes comprising two recessive (er1 and er2) and one dominant (Er3) have been reported to confer resistance to powdery mildew in garden pea. A set of 46 pea genotypes were screened against the E. pisi isolate- Ep01 in greenhouse conditions to identify resistant genotypes. Disease reaction and genotyping were carried out to test for resistance/ susceptibility through gene-specific sequence characterized amplified region (SCAR) markers. The presence of the resistance alleles in the control pea genotypes- JI2302 for er1 gene, JI2480 for er2 gene and P660–4 for Er3 was confirmed through their respective gene-specific markers. The pea genotype- Arkel served as a negative control. Screening of the pea germplasm revealed 3 genotypes as highly resistant, 6 genotypes as resistant while 10 genotypes were moderately resistant, 13 genotypes were moderately susceptible, 9 genotypes were susceptible and 5 were highly susceptible. The molecular marker for er1 resistance gene Sc-OPE-16₁₆₀₀ was found to be segregating in most of the pea genotypes except in the susceptible control- Arkel. The marker- ScX17_1400 for er2 gene was found to be in homozygous condition in the resistant pea genotypes while the marker associated with Er3 resistance, SCW4₆₃₇, was found to be in heterozygous condition in majority of the pea genotypes except in the resistant control genotype- P660–4.

Origin and evolution of secondary cell wall is considered key to colonization of terrestrial habitat by plants. The primary component of secondary cell wall, lignin, imparts strength and rigidity and enables plants to endure negative pressure created during transpiration. Members of the MYB transcription family, AtMYB42 and AtMYB85, play critical roles as regulators of lignin biosynthesis. Inspite of their functional significance, evolutionary history of homologs of AtMYB42 and AtMYB85 across land plants remains to be investigated. Our analysis revealed that homologs of AtMYB42 and AtMYB85 as two distinct genes are not present in any plant lineage outside Brassicaceae and only the ancestral form exists as AtMYB42/AtMYB85. Analysis of homologs of AtMYB42 and AtMYB85 across green plants combined with comparative genomics, selection pressure, and character-state reconstruction reveals that AtMYB42 and AtMYB85 are paralogous, and arose via segmental duplication, which may coincide with the α-event of WGD that occurred after the split of Brassicaceae-Caricaceae from the last common ancestor. Within Brassicaceae, homeologs and paralogs that arose as a result of polyploidization, and species- and lineage-specific changes could be observed. For instance, homologs of AtMYB42 were found to be deleted from the entire Brassica lineage. Analysis of homeologous segments in neopolyploids (B. napus, B. juncea, Camelina sativa), and meso-polyploid (B. rapa) revealed differential degrees of gene loss and retention. In Brassicaceae, homologs of AtMYB42 were found to be under purifying selection and of AtMYB85 under positive selection. High sequence identity in the coding region between homologs of AtMYB42 and AtMYB85 is indicative of redundant roles, and the loss of homologs of AtMYB42 in Brassica may be compensated by presence of AtMYB85 homologs and homeologs. The study thus forms the basis to investigate questions on regulatory diversification owing to variation in cis-elements between the paralogs and among homeologs, and, impact of differential selection pressure vis-a-vis redundant function.

Insect and pathogen damage of maize inhibits sustainable production. Discovery of maize genes coding for products active against both classes of pests would significantly accelerate the rate of development of resistant varieties. A quinone oxidoreductase gene homologous to apoptosis related P53 inducible gene 3 (PIG3) in vertebrates was identified as a pest resistance candidate in a quantitative trait locus region for maize ear rot resistance. The quinone oxidoreductase gene was cloned from a Fusarium resistant inbred of maize and expressed in maize callus. The transformed callus had some significant resistance to the maize pathogen F. graminearum, compared to control transformants, and was often highly resistant to two major caterpillar pests of maize. A band of enhanced reactive oxygen species (ROS) generation in the presence of relevant substrates was noted when protein extracts from the transgenic callus compared to those from control callus were separated by polyacrylamide gel electrophoresis. Thus, presence or introduction of an optimally functional form of this gene should lead to enhanced resistance of maize and other crops to major insect and fungal pests.

MicroRNAs (miRNAs) are a class of small non-coding RNAs that act as important modulators of gene expression related to several stress responses in plants. While several miRNAs have been implicated in the modulation of multiple abiotic and biotic stresses in rice, there role in response to fluoride stress is yet to be explored. In the present study, fourteen conserved rice miRNAs with proven role in multiple stress response were analysed to identify differentially expressed miRNAs in response to fluoride toxicity in two popular rice varieties- Gobindobhog (GB; F-tolerant) and IR64 (F-sensitive). Stem-Loop RT-PCR revealed that miR156, miR166, and miR171 were significantly induced in GB seedlings post treatment with fluoride. Likewise, miR160, miR319, miR396, and miR444 were prominently induced in the fluoride-sensitive IR64. Additionally, miR393 was significantly induced post-treatment with fluoride stress in both the genotypes exhibiting a basal response to fluoride toxicity. Further, we computationally predicted the miRNA targets many of which encoded transcription factors associated with stress response mechanism. The miRNA targets were experimentally validated using ligation mediated 5′ rapid amplification of cDNA ends analysis. Quantitative RT-PCR analysis of nine selected miRNA target genes (Os11g30370, Os06g47150, Os06g03670, Os04g48290, Os02g44360, Os08g34380, Os05g05800, Os04g57050, Os04g51350) revealed simultaneous reciprocal changes in the expression patterns of the miRNAs and the corresponding target genes suggesting their involvement in the modulation of fluoride stress response in rice. Analysis of proximal promoter sequences of the F-responsive miRNAs revealed that these miRNAs possess stress-responsive, elicitor and hormonal related motifs. Overall, our results suggest that multiple conserved miRNAs are involved in fluoride toxicity and a miRNA-mediated regulation of signal response is critical for rice response to fluoride stress.

Melanoxylon brauna is a tree species native to the Atlantic Forest that has great potential for reforestation and urban afforestation. Due to its exploitation, germination difficulties, and absence in afforestation projects, it is currently endangered. Therefore, this study aims to evaluate the diversity and genetic structure in M. brauna matrixes established in multiclonal minigardens through inter simple sequence repeat (ISSR) markers. Plant material of 59 individuals arranged in the multiclonal minigarden was collected for the analyses. Eleven ISSR primers were selected, which generated 183 fragments, among which 117 were polymorphic (63,93%). The efficiency of the markers was confirmed through the polymorphism information content (PIC) which resulted in an average value of 0.36, characterizing them as moderately informative. High genetic diversity was found based on the values of the number of observed alleles (A_O = 2.00) and effective alleles (A_E = 1.63), Nei's diversity index (H* = 0.36), Shannon index (I* = 0.54), and the formation of distinct groups by cluster analysis. Despite the alleles being well distributed among individuals, revealing high genetic diversity, Bayesian inference revealed only one genetic group (K = 1). The ISSR markers proved to be efficient in the characterization of the genetic diversity in M. brauna individuals, and the population of the multiclonal minigarden can be used as a source of propagules for seedling production. However, actions such as the expansion of the genetic diversity through the introduction of plants from different origins can increase the adaptive potential of the minigarden and future established populations.