Guo Yongfeng, Gan Susheng
Department of Horticulture, 119 Plant Science, Cornell University, Ithaca, NY 14853-5904, USA.
Plant J. 2006 May;46(4):601-12. doi: 10.1111/j.1365-313X.2006.02723.x.
Leaf senescence is a unique developmental process that is characterized by massive programmed cell death and nutrient recycling. The underlying molecular regulatory mechanisms are not well understood. Here we report the functional analysis of AtNAP, a gene encoding a NAC family transcription factor. Expression of this gene is closely associated with the senescence process of Arabidopsis rosette leaves. Leaf senescence in two T-DNA insertion lines of this gene is significantly delayed. The T-DNA knockout plants are otherwise normal. The mutant phenotype can be restored to wild-type by the intact AtNAP, as well as by its homologs in rice and kidney bean plants that are also upregulated during leaf senescence. Furthermore, inducible overexpression of AtNAP causes precocious senescence. These data strongly suggest that AtNAP and its homologs play an important role in leaf senescence in Arabidopsis and possibly in other plant species.
叶片衰老 是一个独特的发育过程，其特征是大量的程序性细胞死亡和养分循环利用。其潜在的分子调控机制尚未完全清楚。在此，我们报告了AtNAP的功能分析，AtNAP是一个编码NAC家族转录因子的基因。该基因的表达与拟南芥莲座叶的衰老过程密切相关。该基因的两个T-DNA插入系中的叶片衰老显著延迟。T-DNA敲除植株在其他方面是正常的。完整的AtNAP以及水稻和菜豆中在叶片衰老过程中也上调的同源物可将突变表型恢复为野生型。此外，AtNAP的诱导性过表达会导致早衰。这些数据有力地表明，AtNAP及其同源物在拟南芥的叶片衰老中发挥重要作用，并且可能在其他植物物种中也发挥重要作用。
