Xu Xiangbin, Bai Haiqi, Liu Chaoping, Chen Eryong, Chen Qifeng, Zhuang Jieyun, Shen Bo
College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China.
State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.
PLoS One. 2014 Dec 5;9(12):e114313. doi: 10.1371/journal.pone.0114313. eCollection 2014.
Grain production of rice (Oryza sativa L.) is a top priority in ensuring food security for human beings. One of the approaches to increase yield is to delay leaf senescence and to extend the available time for photosynthesis. MicroRNAs (miRNAs) are key regulators of aging and cellular senescence in eukaryotes. Here, to help understand their biological role in rice leaf senescence, we report identification of miRNAs and their putative target genes by deep sequencing of six small RNA libraries, six RNA-seq libraries and two degradome libraries from the leaves of two super hybrid rice, Nei-2-You 6 (N2Y6, age-resistant rice) and Liang-You-Pei 9 (LYP9, age-sensitive rice). In total 372 known miRNAs, 162 miRNA candidates and 1145 targets were identified. Compared with the expression of miRNAs in the leaves of LYP9, the numbers of miRNAs up-regulated and down-regulated in the leaves of N2Y6 were 47 and 30 at early stage of grain-filling, 21 and 17 at the middle stage, and 11 and 37 at the late stage, respectively. Six miRNA families, osa-miR159, osa-miR160 osa-miR164, osa-miR167, osa-miR172 and osa-miR1848, targeting the genes encoding APETALA2 (AP2), zinc finger proteins, salicylic acid-induced protein 19 (SIP19), auxin response factors (ARF) and NAC transcription factors, respectively, were found to be involved in leaf senescence through phytohormone signaling pathways. These results provided valuable information for understanding the miRNA-mediated leaf senescence of rice, and offered an important foundation for rice breeding.
水稻(Oryza sativa L.)的粮食生产是确保人类粮食安全的首要任务。提高产量的方法之一是延缓叶片衰老,延长光合作用的有效时间。微小RNA(miRNA)是真核生物衰老和细胞衰老的关键调节因子。在此,为了帮助理解它们在水稻叶片衰老中的生物学作用,我们通过对两个超级杂交水稻内-2-优6号(N2Y6,抗早衰水稻)和两优培九(LYP9,早衰敏感水稻)叶片的六个小RNA文库、六个RNA测序文库和两个降解组文库进行深度测序,报告了miRNA及其假定靶基因的鉴定结果。总共鉴定出372个已知miRNA、162个miRNA候选物和1145个靶标。与LYP9叶片中miRNA的表达相比,在灌浆早期,N2Y6叶片中上调和下调的miRNA数量分别为47个和30个;在中期分别为21个和17个;在后期分别为11个和37个。发现分别靶向编码APETALA2(AP2)、锌指蛋白、水杨酸诱导蛋白19(SIP19)、生长素响应因子(ARF)和NAC转录因子的基因的六个miRNA家族,即osa-miR159、osa-miR160、osa-miR164、osa-miR167、osa-miR172和osa-miR1848,通过植物激素信号通路参与叶片衰老。这些结果为理解miRNA介导的水稻叶片衰老提供了有价值的信息,并为水稻育种提供了重要基础。