文献类型： 外文期刊

作者： Xiao, Xian-mei ¹ ; Xu, Yan-mei ¹ ; Zeng, Ze-xiang ¹ ; Tan, Xiao-li ¹ ; Liu, Zong-li ¹ ; Chen, Jian-wen ² ; Su, Xin-guo ³ ;

作者机构： 1.South China Agr Univ, Coll Hort,Key Lab Biol & Genet Improvement Hort C, Minist Educ,Guangdong Prov Key Lab Postharvest Sc, State Key Lab Conservat & Utilizat Subtrop Agrobi, Guangzhou 510642, Guangdong, Peoples R China

2.South China Agr Univ, Coll Agr, Minist Agr, Sci Observing & Expt Stn Crop Cultivat South Chin, Guangzhou 510642, Guangdong, Peoples R China

3.Guangdong Food & Drug Vocat Coll, Dept Food Sci, Guangzhou 510520, Guangdong, Peoples R China

关键词： Chinese flowering cabbage; GA; leaf senescence; transcriptional activation

期刊名称：INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES （ 影响因子：5.923； 五年影响因子：6.132 ）

ISSN： 1661-6596

年卷期： 2019 年 20 卷 16 期

页码：

收录情况： SCI

摘要： Several lines of evidence have implicated the involvement of the phytohormone gibberellin (GA) in modulating leaf senescence in plants. However, upstream transcription factors (TFs) that regulate GA biosynthesis in association with GA-mediated leaf senescence remain elusive. In the current study, we report the possible involvement of a TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TF BrTCP21 in GA-delayed leaf senescence in Chinese flowering cabbage. Exogenous GA(3) treatment maintained a higher value of maximum PSII quantum yield (Fv/Fm) and total chlorophyll content, accompanied by the repression of the expression of senescence-associated genes and chlorophyll catabolic genes, which led to the delay of leaf senescence. A class I member of TCP TFs BrTCP21, was further isolated and characterized. The transcript level of BrTCP21 was low in senescing leaves, and decreased following leaf senescence, while GA(3) could keep a higher expression level of BrTCP21. BrTCP21 was further found to be a nuclear protein and exhibit trans-activation ability through transient-expression analysis in tobacco leaves. Intriguingly, the electrophoretic mobility shift assay (EMSA) and transient expression assay illustrated that BrTCP21 bound to the promoter region of a GA biosynthetic gene BrGA20ox3, and activated its transcription. Collectively, these observations reveal that BrTCP21 is associated with GA-delayed leaf senescence, at least partly through the activation of the GA biosynthetic pathway. These findings expand our knowledge on the transcriptional mechanism of GA-mediated leaf senescence.