Buti Matteo, Pasquariello Marianna, Ronga Domenico, Milc Justyna Anna, Pecchioni Nicola, Ho Viet The, Pucciariello Chiara, Perata Pierdomenico, Francia Enrico
BIOGEST-SITEIA, University of Modena and Reggio Emilia, Via Amendola, 2 - Pad. Besta, 42122, Reggio Emilia, Italy.
Department of Crop Genetics, John Innes Centre, Norwich, UK.
Funct Integr Genomics. 2018 Nov;18(6):627-644. doi: 10.1007/s10142-018-0615-y. Epub 2018 Jun 6.
Low temperature is a major factor limiting rice growth and yield, and seedling is one of the developmental stages at which sensitivity to chilling stress is higher. Tolerance to chilling is a complex quantitative trait, so one of the most effective approaches to identify genes and pathways involved is to compare the stress-induced expression changes between tolerant and sensitive genotypes. Phenotypic responses to chilling of 13 Japonica cultivars were evaluated, and Thaibonnet and Volano were selected as sensitive and tolerant genotypes, respectively. To thoroughly profile the short-term response of the two cultivars to chilling, RNA-Seq was performed on Thaibonnet and Volano seedlings after 0 (not stressed), 2, and 10 h at 10 °C. Differential expression analysis revealed that the ICE-DREB1/CBF pathway plays a primary role in chilling tolerance, mainly due to some important transcription factors involved (some of which had never been reported before). Moreover, the expression trends of some genes that were radically different between Thaibonnet and Volano (i.e., calcium-dependent protein kinases OsCDPK21 and OsCDPK23, cytochrome P450 monooxygenase CYP76M8, etc.) suggest their involvement in low temperature tolerance too. Density of differentially expressed genes along rice genome was determined and linked to the position of known QTLs: remarkable co-locations were reported, delivering an overview of genomic regions determinant for low temperature response at seedling stage. Our study contributes to a better understanding of the molecular mechanisms underlying rice response to chilling and provides a solid background for development of low temperature-tolerant germplasm.
低温是限制水稻生长和产量的主要因素，而幼苗期是对冷害胁迫较为敏感的发育阶段之一。耐冷性是一个复杂的数量性状，因此，识别相关基因和途径最有效的方法之一是比较耐冷和敏感基因型之间胁迫诱导的表达变化。评估了13个粳稻品种对冷害的表型反应，分别选择泰国黑米和沃拉诺作为敏感型和耐冷型基因型。为了全面描述这两个品种对冷害的短期反应，在10℃处理0（未胁迫）、2和10小时后，对泰国黑米和沃拉诺幼苗进行了RNA测序。差异表达分析表明，ICE-DREB1/CBF途径在耐冷性中起主要作用，这主要归因于一些重要的转录因子（其中一些以前从未报道过）。此外，泰国黑米和沃拉诺之间一些基因的表达趋势存在根本差异（即钙依赖性蛋白激酶OsCDPK21和OsCDPK23、细胞色素P450单加氧酶CYP76M8等），这表明它们也参与了低温耐受性。确定了水稻基因组上差异表达基因的密度，并将其与已知QTL的位置联系起来：报告了显著的共定位情况，概述了决定幼苗期低温反应的基因组区域。我们的研究有助于更好地理解水稻对冷害反应的分子机制，并为耐低温种质的开发提供了坚实的背景。
