Project description:Brown planthopper (BPH; Nilaparvata lugens) is a phloem feeding insect which is one of the most serious threats to rice crops in many countries throughout Asia. 1H NMR spectroscopy, combined with chemometrics, was used to analyze the polar metabolome from leaf extracts of Thai Jasmine rice (brown planthopper (BPH)-susceptible KD) and its BPH resistant isogenic lines (BPH-resistant IL7 and BPH-resistant+ IL308 varieties) with and without BPH infestation at various time points (days 1, 2, 3, 4 and 8). Physiological changes of the rice isogenic lines were different based on the quantitative trait loci of BPH resistance. Multivariate models were capable of distinguishing between the susceptible and the resistant rice varieties throughout the infestation. The concentration of 10 metabolites were significantly altered (p < 0.05) between the infested and the control groups of each examined rice variety. Metabolic pathway analysis suggested that BPH infestation could perturb transamination during the early stages of infestation (days 1–3) for all rice varieties. In addition, the IL7 and IL308 varieties responded earlier (day 3) than the KD variety (day 8) by perturbing amino acid metabolism, shikimate and gluconeogenesis pathways. By day 8 of the infestation, the KD cultivar responded by activating the amino acid-mediated-de novo pathway whereas the IL308 variety activated the purine and pyrimidine compound-mediated-salvage pathway for nucleotide biosynthesis. This study has identified, for the first time, several potential metabolic pathways for acclimatization and defense mechanisms against BPH infestation. These findings provide a valuable, first insight into BPH resistance mechanisms in Thai Jasmine rice.
Project description:A biological phenomenon in which hybrids exhibit superior phenotypes from its parental inbred lines known as heterosis, has been widely exploited in plant breeding and extensively used in crop improvement. Hybrid rice has immense potential to increase yield over other rice varieties and hence is crucial in meeting increasing demand of rice globally. Moreover, the molecular basis of heterosis is still not fully understood and hence it becomes imperative to unravel its genetic and molecular basis. In this context, RNA sequencing technology (RNA-Seq) was employed to sequence transcriptomes of two rice hybrids, Ajay and Rajalaxmi, their parental lines, CRMS31A (sterile line, based on WA-CMS) and CRMS32A (sterile line based on Kalinga-CMS) respectively along with the common restorer line of both hybrids, IR-42266-29-3R at two critical rice developmental stages viz., panicle initiation (PI) and grain filling (GF). Identification of differentially expressed genes (DEGs) at PI and GF stages will further pave the way for understanding heterosis. In addition, such kind of study would help in better understanding of heterosis mechanism and genes up-regulated and down-regulated during the critical stages of rice development for higher yield.
Project description:5 leaves old rice plantlets were infected with Magnaporthe grisea spores and zero, two hours and twenty four houres after infection samples were collected
Project description:In order to identify new miRNAs, NAT-siRNAs and possibly abiotic-stress regulated small RNAs in rice, three small RNA libraries were constructed from control rice seedlings and seedlings exposed to drought or salt stress, and then subjected to pyrosequencing.
Project description:LongSAGE library in this series are from 'Whole Genome Analysis of Pathogen-Host Recognition and Subsequent Responses in the Rice Blast Patho-System' project. This work is supported by NSF-PGRP #0115642. Keywords: other
Project description:Rice is one of the most important global food crops, and is also a model organism for cereal research 31 . Complete genome sequencing of rice, together with advances in transcriptomics and proteomics, has had a dramatic impact on plant growth and 5 breeding programs 32 . Genomic analysis of DNA methylation in rice has revealed methylation patterns associated with gene bodies and promoters, and the occurrence of high levels of DNA methylation in the centromeric domain 33 . A genome-wide investigation of acetylation in rice revealed that H3K9ac and H3K27ac are mainly enriched at transcription start sites associated with active transcription 34 . Furthermore, global proteome analysis has shown that phosphorylation and succinylation are involved in diverse cellular and metabolic processes 35, 36 . However, despite these considerable advances in our knowledge, additional large-scale analysis of the lysine acetylome in rice is expected to identify many more Kac sites and acetylated proteins in this improtant crop plant. In this study, affinity enrichment and high-resolution LC-MS/MS were used for large-scale analysis of the lysine acetylome in rice variety Nipponbare. In total, 1353 lysine acetylation sites were detected in 866 protein groups in rice seedlings. Proteomic analysis showed that Kac occurs in proteins involved in diverse biological processes with varied cellular functions and subcellular localization.
Project description:Using microarray, the anther transcript profiles of the three indica rice CMS lines revealed 622 differentially expression genes (DEGs) in each of the three CMS lines. GO and Mapman analysis indicated that these DEGs were mainly involved in lipid metabolic and cell wall organization. Comprised with the gene expression of sporophytic and gametophytic CMS lines, 303 DEGs were differentially expressed and 56 of them were down-regulated in all the CMS lines. Co-expression network analysis suggested that many genes were significantly differentially expressed in the CMS lines. These down-regulated DEGs in the CMS lines were found to be involved in tapetum or cell wall formation and their suppressed expression might be related to male sterility. The present study will give some information for the nuclear gene regulation by different cytoplasmic genotypes and provide some candidate genes for pollen development in rice.
Project description:High-throughput single-base resolution bisulfite sequencing (BS-Seq) was carried out to analyze the distribution pattern and characteristics of cytosine methylation in RBSDV-infected rice. Widespread differences were identified at CG and non-CG contexts between the RBSDV-infected and RBSDV-free rice. We identified a large number of differentially methylated regions (DMRs) along the genome of RBSDV-infected rice. And meanwhile, the transcriptome sequencing analysis obtained 1119 differentially expressed genes (DEGs). Correlation analysis of DMRs-related genes (DMGs) and DEGs filtered 71 genes with negative relationship between methylation level at promoter regions and gene expression. Many of them were significantly enriched in the KEGG pathways of biosynthesis of amino acids, plant-pathogen interaction and plant hormone signal transduction.
Project description:To understand the dynamics and global gene reprogramming in the early response to mechanical wounding in rice, the transcriptional response to mechanical injury was analyzed. A time-course experiment revealed the highly dynamic nature of the wound response in rice. Mechanical wounding triggered extensive gene expression reprogramming in the locally wounded leaf, affecting various physiological processes, including defense mechanisms and potentially tissue repair and regeneration. The rice response to mechanical wounding displayed both differences and similarities compared to the response to jasmonate treatment. These results highlight the importance of early JA signaling in response to mechanical stress in rice. This analysis provides an overview of the global transcriptional response to mechanical stress in rice, offering valuable insights for future studies on rice's response to injury, insect attack, and abiotic stresses.