GSE112547
Physiological and genome-wide expression analysis of cold-induced leaf rolling at the seedling stage in rice (Oryza sativa L.)
Leaf rolling and discoloration are two chilling injury symptoms that are widely adopted as indicators for evaluation of cold tolerance at the seedling stage in rice, respectively. However, their relationship has not been well investigated, in particular the mechanism on how low temperature causes leaf rolling at a genome-wide level. In this study, a cold-tolerant japonica cultivar Lijiangxintuanheigu and a cold-sensitive indica cultivar Sanhuangzhan-2 were subjected to different low temperature treatments and physiological and genome-wide gene expression analysis were conducted. Our results showed that leaf rolling happened at temperatures lower than 11?, but discoloration appeared at moderately low temperatures, such as 13?. Chlorophyll contents of the two cultivars significantly decreased under 13?, but didn't change under 11?. Contrastly, their relative water contents and the relative electrolyte leakages decreased significantly. Genome-wide gene expression profiling of LTH revealed that the calcium signaling related genes and the genes related to ABA degradation significantly changed under 11?. Moreover, numerous genes in DREB, MYB, bZIP, NAC, Zin finger, bHLH, WRKY gene families were differently expressed. Furthermore, many aquaporin genes, the key genes in trehalose and starch synthesis were down-regulated under 11?. These results suggest that the two chilling injury symptoms are controlled by different mechanisms. Cold-induced leaf rolling is associated with calcium and ABA signaling pathways, and subjected to regulation of multiple transcription regulators. The suppression of aquaporin genes and reduced accumulation of soluble sugars under cold stress result in reduction of water potential in cells and consequently, leaf rolling. Overall design: mRNA profiles of Lijiangxintuanheigu (LTH) rice under 11?,13? and 25? cold stresses for 24h were generated by deep sequencing, in two biological replicates, using Illumina Hiseq 2500 platform.