大豆生长素响应因子GmARF16参与调节叶片衰老进程

Gm ARF16,an Auxin Response Factor,Regulates Leaf Senescence Processes in Glycine max

生长素响应因子(auxin response factors,ARFs)通过调节下游靶基因广泛参与植物生长发育过程,但ARFs如何调控植物叶片衰老的分子机制还不清楚。该文首先利用实时荧光定量PCR(q PCR)技术,分析大豆生长素响应基因Gm ARF16在叶片自然衰老、人工黑暗诱导衰老、外源植物生长素IAA处理条件下的表达模式,结果表明,该基因与叶片衰老调控密切相关,并且属于生长素的原初响应基因。为了进一步验证Gm ARF16基因的功能,采用农杆菌转化方法分别获得基因敲减(Gm ARF16-RNAi)和抗降解表达(m Gm ARF16)的转基因大豆植株。与非转基因对照相比,Gm ARF16-RNAi转基因大豆植株的叶片叶绿素含量和最大光量子效率(Fv/Fm)显著提高,叶片衰老标记基因(Gm CYSP1)的表达受到抑制,而m Gm ARF16转基因大豆植株则呈现出与Gm ARF16-RNAi转基因大豆植株相反的叶片生理表型。结果表明大豆生长素响应因子Gm ARF16正调节叶片的衰老进程。该研究表明,Gm ARF16在植物生长发育进程中发挥着重要作用。

Auxin response factors （ARFs） regulate many processes of plant growth and development by ac- tivating or repressing their targets through the special domain. However, the molecular mechanism of the ARFs reg- ulating leaf senescence is largely unknown. In this paper, expression pattern of GmARF16 was examined by quanti- tative real-time PCR （qPCR）. It showed that transcript of GmARF16 was tightly associated with leaf senescence and exhibited characteristic of the auxin primary response gene. To further investigate the function of GmARF16, both the knock down and the resistant-version transgenic soybean plants were created by Agrobacterium-mediated trans- formation. The knock down plants expressing GmARF16-RNAi exhibited increasing chlorophyll content, higher maximum quantum efficiency （Fv/Fm） and up-regulated GmCYSP1, a soybean senescence marker. In contrast, the leaves of resistant-version transgenic plants expressing mGmARF16 showed opposite phenotypes compared with non-transgenic controls, indicating that GmARF 16 regulates leaf senescence as a positive regulator. The results of this work highlight the role of GmARF16 in plant development.