Baldoni Elena, Bagnaresi Paolo, Locatelli Franca, Mattana Monica, Genga Annamaria
Institute of Agricultural Biology and Biotechnology - National Research Council, via Bassini 15, 20133, Milan, Italy.
Dipartimento di Scienze Agrarie e Ambientali - Produzione, Territorio, Agroenergia, Università degli Studi di Milano, Via Celoria 2, 20133, Milan, Italy.
Rice (N Y). 2016 Dec;9(1):25. doi: 10.1186/s12284-016-0098-1. Epub 2016 May 23.
Rice (Oryza sativa L.) is one of the most important crops cultivated in both tropical and temperate regions and is characterized by a low water-use efficiency and a high sensitivity to a water deficit, with yield reductions occurring at lower stress levels compared to most other crops. To identify genes and pathways involved in the tolerant response to dehydration, a powerful approach consists in the genome-wide analysis of stress-induced expression changes by comparing drought-tolerant and drought-sensitive genotypes.
The physiological response to osmotic stress of 17 japonica rice genotypes was evaluated. A clear differentiation of the most tolerant and the most sensitive phenotypes was evident, especially after 24 and 48 h of treatment. Two genotypes, which were characterized by a contrasting response (tolerance/sensitivity) to the imposed stress, were selected. A parallel transcriptomic analysis was performed on roots and leaves of these two genotypes at 3 and 24 h of stress treatment. RNA-Sequencing data showed that the tolerant genotype Eurosis and the sensitive genotype Loto mainly differed in the early response to osmotic stress in roots. In particular, the tolerant genotype was characterized by a prompt regulation of genes related to chromatin, cytoskeleton and transmembrane transporters. Moreover, a differential expression of transcription factor-encoding genes, genes involved in hormone-mediate signalling and genes involved in the biosynthesis of lignin was observed between the two genotypes.
Our results provide a transcriptomic characterization of the osmotic stress response in rice and identify several genes that may be important players in the tolerant response.
水稻（Oryza sativa L.）是热带和温带地区种植的最重要作物之一，其特点是水分利用效率低，对水分亏缺高度敏感，与大多数其他作物相比，在较低胁迫水平下就会出现产量下降。为了鉴定参与脱水耐受反应的基因和途径，一种有效的方法是通过比较耐旱和干旱敏感基因型，对胁迫诱导的表达变化进行全基因组分析。
评估了17个粳稻基因型对渗透胁迫的生理反应。最耐受和最敏感表型之间有明显差异，尤其是在处理24小时和48小时后。选择了两个对施加的胁迫有相反反应（耐受/敏感）的基因型。在胁迫处理3小时和24小时时，对这两个基因型的根和叶进行了平行转录组分析。RNA测序数据表明，耐受基因型Eurosis和敏感基因型Loto在根对渗透胁迫的早期反应中主要存在差异。特别是，耐受基因型的特征是与染色质、细胞骨架和跨膜转运蛋白相关的基因迅速调控。此外，在这两个基因型之间观察到转录因子编码基因、参与激素介导信号传导的基因以及参与木质素生物合成的基因的差异表达。
我们的结果提供了水稻渗透胁迫反应的转录组特征，并鉴定了几个可能在耐受反应中起重要作用的基因。
