Project description:The expression of 30362 plant genes from uninfected flowers of Boechera stricta, uninfected steam and leaves of B. stricta and infected B. stricta with Puccinia monoica forming pseudoflowers. We hybridized cDNA from each sample to an Arabidopsis thaliana gene expression 4x72K format NimbleGen array (ATH6_60mer_expr).
Project description:The expression of 30362 plant genes from uninfected flowers of Boechera stricta, uninfected steam and leaves of B. stricta and infected B. stricta with Puccinia monoica forming pseudoflowers. We hybridized cDNA from each sample to an Arabidopsis thaliana gene expression 4x72K format NimbleGen array (ATH6_60mer_expr). We used a eukaryotic gene expression array design No.5048 from NimbleGen (Cat No. A4511001-00-01). Each 5048 array measures the expression level of 30,362 target genes from Arabidopsis thaliana in a 4-plex format 4x72K with with 72,000 probes per array, a total of two probes per target gene, and 60-mer probe length. Total RNA samples recovered from infected leaves of Boechera stricta with Puccinia monoica (pseudoflowers) and uninfected stem and leaves of B. stricta. Experiments included three/two biological repllicates from each sample. We carried out total RNA extractions for all samples using RNAesy Plant Mini Kit (Qiagen, Cat No. 74904). cDNA synthesis was performed by NimbleGen.
Project description:Climate change is predicted to be a serious threat to agriculture due to the need for crops to be able to tolerate increased heat stress. Desert plants have already adapted to high levels of heat stress so they make excellent systems for identifying genes involved in thermotolerance. Rhazya stricta is an evergreen shrub that is native to extremely hot regions across Western and South Asia, making it an excellent system for examining plant responses to heat stress. Transcriptomes of apical and mature leaves of R. stricta were analyzed at different temperatures during several time points of the day to detect heat response mechanisms that might confer thermotolerance and protection of the plant photosynthetic apparatus.Biological pathways that were crosstalking during the day involved the biosynthesis of several heat stress-related compounds, including soluble sugars, polyols, secondary metabolites, phenolics and methionine. Highly downregulated leaf transcripts at the hottest time of the day (40-42.4 °C) included genes encoding cyclin, cytochrome p450/secologanin synthase and U-box containing proteins, while upregulated, abundant transcripts included genes encoding heat shock proteins (HSPs), chaperones, UDP-glycosyltransferase, aquaporins and protein transparent testa 12. The upregulation of transcripts encoding HSPs, chaperones and UDP-glucosyltransferase and downregulation of transcripts encoding U-box containing proteins likely contributed to thermotolerance in R. stricta leaf by correcting protein folding and preventing protein degradation. Transcription factors that may regulate expression of genes encoding HSPs and chaperones under heat stress included HSFA2 to 4, AP2-EREBP and WRKY27.This study contributed new insights into the regulatory mechanisms of thermotolerance in the wild plant species R. stricta, an arid land, perennial evergreen shrub common in the Arabian Peninsula and Indian subcontinent. Enzymes from several pathways are interacting in the biosynthesis of soluble sugars, polyols, secondary metabolites, phenolics and methionine and are the primary contributors to thermotolerance in this species.
Project description:Rhazya stricta is an evergreen shrub that is widely distributed across Western and South Asia, and like many other members of the Apocynaceae produces monoterpene indole alkaloids that have anti-cancer properties. This species is adapted to very harsh desert conditions making it an excellent system for studying tolerance to high temperatures and salinity. RNA-Seq analysis was performed on R. stricta exposed to severe salt stress (500 mM NaCl) across four time intervals (0, 2, 12 and 24 h) to examine mechanisms of salt tolerance. A large number of transcripts including genes encoding tetrapyrroles and pentatricopeptide repeat (PPR) proteins were regulated only after 12 h of stress of seedlings grown in controlled greenhouse conditions. Mechanisms of salt tolerance in R. stricta may involve the upregulation of genes encoding chaperone protein Dnaj6, UDP-glucosyl transferase 85a2, protein transparent testa 12 and respiratory burst oxidase homolog protein b. Many of the highly-expressed genes act on protecting protein folding during salt stress and the production of flavonoids, key secondary metabolites in stress tolerance. Other regulated genes encode enzymes in the porphyrin and chlorophyll metabolic pathway with important roles during plant growth, photosynthesis, hormone signaling and abiotic responses. Heme biosynthesis in R. stricta leaves might add to the level of salt stress tolerance by maintaining appropriate levels of photosynthesis and normal plant growth as well as by the participation in reactive oxygen species (ROS) production under stress. We speculate that the high expression levels of PPR genes may be dependent on expression levels of their targeted editing genes. Although the results of PPR gene family indicated regulation of a large number of transcripts under salt stress, PPR actions were independent of the salt stress because their RNA editing patterns were unchanged.