Yuan Jianbo, Sun Xinbo, Guo Tao, Chao Yuehui, Han Liebao
College of Grassland Science, Beijing Forestry University, Beijing, China.
College of Agronomy, Hebei Agricultural University, Key Laboratory of Crop Growth Regulation of Hebei Province, China.
PeerJ. 2020 Jan 21;8:e8426. doi: 10.7717/peerj.8426. eCollection 2020.
Leaf senescence is a complex organized developmental stage limiting the yield of crop plants, and alfalfa is an important forage crop worldwide. However, our understanding of the molecular mechanism of leaf senescence and its influence on biomass in alfalfa is still limited. In this study, RNA sequencing was utilized to identify differentially expressed genes (DEGs) in young, mature, and senescent leaves, and the functions of key genes related to leaf senescence. A total of 163,511 transcripts and 77,901 unigenes were identified from the transcriptome, and 5,133 unigenes were differentially expressed. KEGG enrichment analyses revealed that ribosome and phenylpropanoid biosynthesis pathways, and starch and sucrose metabolism pathways are involved in leaf development and senescence in alfalfa. GO enrichment analyses exhibited that six clusters of DEGs are involved in leaf morphogenesis, leaf development, leaf formation, regulation of leaf development, leaf senescence and negative regulation of the leaf senescence biological process. The WRKY and NAC families of genes mainly consist of transcription factors that are involved in the leaf senescence process. Our results offer a novel interpretation of the molecular mechanisms of leaf senescence in alfalfa.
叶片衰老 是一个复杂的有组织的发育阶段，限制了农作物的产量，而苜蓿是全球重要的饲料作物。然而，我们对苜蓿叶片衰老的分子机制及其对生物量的影响的了解仍然有限。在本研究中，利用RNA测序来鉴定幼叶、成熟叶和衰老叶中差异表达的基因（DEG），以及与叶片衰老相关的关键基因的功能。从转录组中总共鉴定出163,511个转录本和77,901个单基因，其中5,133个单基因差异表达。KEGG富集分析表明，核糖体和苯丙烷生物合成途径以及淀粉和蔗糖代谢途径参与苜蓿叶片的发育和衰老。GO富集分析显示，六组差异表达基因参与叶片形态发生、叶片发育、叶片形成、叶片发育调控、叶片衰老以及叶片衰老生物过程的负调控。WRKY和NAC基因家族主要由参与叶片衰老过程的转录因子组成。我们的结果为苜蓿叶片衰老的分子机制提供了新的解释。
