1. A Rice PECTATE LYASE-LIKE Gene Is Required for Plant Growth and Leaf Senescence
- Author
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Zhaosheng Kong, Yuqiong Wang, Deyong Ren, Zhenyu Gao, Long Chen, Liping Dai, Lichao Huang, Li Zhu, Longbiao Guo, Yaolong Yang, Zhengjun Tu, Jiang Hu, Yujia Leng, Yihong Gao, Qian Qian, Dali Zeng, Xueyong Li, Guangheng Zhang, and Yongjun Lin
- Subjects
0106 biological sciences ,0301 basic medicine ,Genetics ,Senescence ,Regulation of gene expression ,Physiology ,fungi ,Mutant ,food and beverages ,Plant Science ,Cell cycle ,Biology ,01 natural sciences ,Cell biology ,Cell wall ,Transcriptome ,03 medical and health sciences ,030104 developmental biology ,Pectate lyase ,Gene expression ,010606 plant biology & botany - Abstract
To better understand the molecular mechanisms behind plant growth and leaf senescence in monocot plants, we identified a mutant exhibiting dwarfism and an early-senescence leaf phenotype, termed dwarf and early-senescence leaf1 (del1). Histological analysis showed that the abnormal growth was caused by a reduction in cell number. Further investigation revealed that the decline in cell number in del1 was affected by the cell cycle. Physiological analysis, transmission electron microscopy, and TUNEL assays showed that leaf senescence was triggered by the accumulation of reactive oxygen species. The DEL1 gene was cloned using a map-based approach. It was shown to encode a pectate lyase (PEL) precursor that contains a PelC domain. DEL1 contains all the conserved residues of PEL and has strong similarity with plant PelC. DEL1 is expressed in all tissues but predominantly in elongating tissues. Functional analysis revealed that mutation of DEL1 decreased the total PEL enzymatic activity, increased the degree of methylesterified homogalacturonan, and altered the cell wall composition and structure. In addition, transcriptome assay revealed that a set of cell wall function- and senescence-related gene expression was altered in del1 plants. Our research indicates that DEL1 is involved in both the maintenance of normal cell division and the induction of leaf senescence. These findings reveal a new molecular mechanism for plant growth and leaf senescence mediated by PECTATE LYASE-LIKE genes.
- Published
- 2017