Comparative transcriptome analysis of panicle development under heat stress in two rice (Oryza sativaL.) cultivars differing in heat tolerance

Abstract

Heat stress inhibits rice panicle development and reduces the spikelet number per panicle. This study investigated the mechanism involved in heat-induced damage to panicle development and spikelet formation in rice cultivars that differ in heat tolerance. Transcriptome data from developing panicles grown at 40 °C or 32 °C were compared for two rice cultivars: heat-tolerant Huanghuazhan and heat-susceptible IR36. Of the differentially expressed genes (DEGs), 4,070 heat stress-responsive genes were identified, including 1,688 heat-resistant-cultivar-related genes (RHR), 707 heat-susceptible-cultivar-related genes (SHR), and 1,675 common heat stress-responsive genes (CHR). A Gene Ontology (GO) analysis showed that the DEGs in the RHR category were significantly enriched in 54 gene ontology terms, some of which improved heat tolerance, including those in the WRKY, HD-ZIP, ERF, and MADS transcription factor families. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEGs in the RHR and SHR categories were enriched in 15 and 11 significant metabolic pathways, respectively. Improved signal transduction capabilities of endogenous hormones under high temperature seemed to promote heat tolerance, while impaired starch and sucrose metabolism under high temperature might have inhibited young panicle development. Our transcriptome analysis provides insights into the different molecular mechanisms of heat stress tolerance in developing rice.

The potential of resilient carbon dynamics for stabilizing crop reproductive development and productivity during heat stress

“…Tomato is particularly sensitive to high temperatures during flowering (Gonzalo et al, 2020), consequently exploring the importance of BZR1 in this context may represent an interesting approach for mitigating heat stress. A gene involved in photosynthetic regulation, ARABIDOSPSIS TRANSCRIPTION ACTIVATION FACTOR 1 (ATAF1), was observed to be significantly up-regulated in our querying of differentially expressed genes in rice panicles in response to heat stress (Figure 2d; Wang, Zhang, et al, 2019). ATAF1 has been identified as a master-regulator of multiple genes that elicit autophagy in response to carbon starvation by facilitating amino acid catabolism, thereby allowing the use of free amino acids as alternative respiratory substrates (Garapati et al, 2015).…”

“…Differentially expressed genes involved in reproductive development and photosynthetic regulation in response to heat stress in reproductive tissues. Left barplots (a,b) show differential expression during heat stress of genes involved in reproductive development in A. thaliana pollen (Data obtained from Rahmati Ishka et al, 2018) and rice panicles respectively (Data obtained from Wang, Zhang, et al, 2019). Right barplots (c,d) show differential expression during heat stress of genes involved in photosynthesis (Wang, Hendron, & Kelly, 2017) in A. thaliana pollen and rice panicles from the same datasets.…”

“…Genes involved in tapetum development are also affected as reflected by our querying of differential expression in rice panicles during heat stress (Figure 2b). Mutants in transcription factor genes DYSFUNCTIONAL TAPETUM1 (DYT1) and ABORTED , 2018) and rice panicles respectively (Data obtained from Wang, Zhang, et al, 2019). Right barplots (c,d) show differential expression during heat stress of genes involved in photosynthesis (Wang, Hendron, & Kelly, 2017) (Sorensen et al, 2003;Zhang et al, 2006).…”

Can omics deliver temperature resilient ready-to-grow crops?

“…Some genes were found to participate in acetylation and methylation in anthers at HS [90]. In another study, transcriptome analysis was conducted between a susceptible and resistant rice genotype under HS for its impact on panicle development [78]. A total of 4070 DEGs were identified and categorized into three groups, such as heat- Cold-induced sweetening (CIS) was observed in tubers when exposed to CS (2-4 C).…”

Comparative analysis of transcriptome and metabolome uncovers the metabolic differences between Dendrobium officinale protocorms and mature stems

“…To further identify their biological functions, these DEGs were subjected to GO enrichment analysis. GO is a model biological framework that defines concepts used to describe gene function, and relationships between these concepts (Ana et al 2005;Sato et al 2019;Wang et al 2019). Based on sequence homology, DEGs were assigned to three general categories: cellular component (CC), molecular function (MF), and biological process (BP).…”