Wang Ying-Ge, Fu Feng-Ling, Yu Hao-Qiang, Hu Tao, Zhang Yuan-Yuan, Tao Yi, Zhu Jian-Kang, Zhao Yang, Li Wan-Chen
Maize Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.
Shanghai Center for Plant Stress Biology, and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
Plant Mol Biol. 2018 Feb;96(3):245-263. doi: 10.1007/s11103-017-0692-7. Epub 2018 Jan 17.
We defined a comprehensive core ABA signaling network in monocot maize, including the gene expression, subcellular localization and interaction network of ZmPYLs, ZmPP2Cs, ZmSnRK2s and the putative substrates. The phytohormone abscisic acid (ABA) plays an important role in plant developmental processes and abiotic stress responses. In Arabidopsis, ABA is sensed by the PYL ABA receptors, which leads to binding of the PP2C protein phosphatase and activation of the SnRK2 protein kinases. These components functioning diversely and redundantly in ABA signaling are little known in maize. Using Arabidopsis pyl112458 and snrk2.2/3/6 mutants, we identified several ABA-responsive ZmPYLs and ZmSnRK2s, and also ZmPP2Cs. We showed the gene expression, subcellular localization and interaction network of ZmPYLs, ZmPP2Cs, and ZmSnRK2s, and the isolation of putative ZmSnRK2 substrates by mass spectrometry in monocot maize. We found that the ABA dependency of PYL-PP2C interactions is contingent on the identity of the PP2Cs. Among 238 candidate substrates for ABA-activated protein kinases, 69 are putative ZmSnRK2 substrates. Besides homologs of previously reported putative AtSnRK2 substrates, 23 phosphoproteins have not been discovered in the dicot Arabidopsis. Thus, we have defined a comprehensive core ABA signaling network in monocot maize and shed new light on ABA signaling.
我们在单子叶植物玉米中定义了一个全面的核心脱落酸（ABA）信号网络，包括ZmPYLs、ZmPP2Cs、ZmSnRK2s及其假定底物的基因表达、亚细胞定位和相互作用网络。植物激素脱落酸（ABA）在植物发育过程和非生物胁迫响应中起重要作用。在拟南芥中，ABA由PYL ABA受体感知，这导致PP2C蛋白磷酸酶的结合和SnRK2蛋白激酶的激活。这些在ABA信号传导中发挥不同和冗余功能的组分在玉米中鲜为人知。利用拟南芥pyl112458和snrk2.2/3/6突变体，我们鉴定了几个ABA响应性ZmPYLs和ZmSnRK2s，以及ZmPP2Cs。我们展示了ZmPYLs、ZmPP2Cs和ZmSnRK2s的基因表达、亚细胞定位和相互作用网络，并通过质谱法在单子叶植物玉米中分离了假定的ZmSnRK2底物。我们发现PYL-PP2C相互作用对ABA的依赖性取决于PP2Cs的身份。在238个ABA激活蛋白激酶的候选底物中，69个是假定的ZmSnRK2底物。除了先前报道的假定AtSnRK2底物的同源物外，23种磷酸化蛋白在双子叶植物拟南芥中尚未被发现。因此，我们在单子叶植物玉米中定义了一个全面的核心ABA信号网络，并为ABA信号传导提供了新的线索。
