Chinese Bulletin of Botany ›› 2019, Vol. 54 ›› Issue (1): 46-57.DOI: 10.11983/CBB18045

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Heterologous Overexpression of Rice OsSAPP3 Gene Promotes Leaf Senescence in Transgenic Arabidopsis

Shengnan Cui1,2,Yihan Zhang1,Fan Xu1,*()   

  1. 1 Key Laboratory of Northeast Rice Biology and Breeding, Ministry of Agriculture, Key Laboratory of Northern Japonica Rice Genetics and Breedings, Ministry of Education, Rice Research Institute, Shenyang Agriculture University, Shenyang 110866, China
    2 Fushun Sifang Senior High School, Fushun 113122, China
  • Received:2018-02-12 Accepted:2018-05-21 Online:2019-01-30 Published:2019-07-31
  • Contact: Fan Xu

Abstract: Protein phosphatase-catalyzed reversible phosphorylation of proteins is a key aspect of leaf senescence. We screened and cloned a new PP2C gene, OsSAPP3, involved in leaf senescence regulation in rice. The promoter of OsSAPP3 was active in rosette leaves of ProOsSAPP3-GUS transgenic Arabidopsis and its activity increased with leaf age. With heterologous overexpression of OsSAPP3 driven by a CaMV 35S promoter, transgenic Arabidopsis could not grow normally. Therefore, OsSAPP3 heterologous overexpression was induced by the inducible promoter GVG system. Exo- genous inducible heterologous overexpression of OsSAPP3 led to a precocious leaf senescence phenotype in transgenic Arabidopsis including smaller rosette leaves and increased number, premature leaf senescence, and advanced bolting and flowering. Additionally, quantitative RT-PCR showed that exogenous inducible heterologous overexpression of OsSAPP3 upregulated the expression of critical senescence-related transcription factor genes, including SAG12, WRKY6, and NAC2. In summary, OsSAPP3 is a positive factor involved in regulating leaf senescence in rice.

Key words: Arabidopsis, leaf senescence, OsSAPP3, 2C type protein phosphatase