Functional Characterization of a Drought-Responsive Invertase Inhibitor from Maize (Zea mays L.)
Functional Characterization of a Drought-Responsive Invertase Inhibitor from Maize (Zea mays L.)
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玉米 (Zea mays L.) 干旱响应型转化酶抑制剂的功能表征
DOI：
10.3390/ijms20174081
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发表时间：
2019-09-01
影响因子：
5.6
通讯作者：
Zhao, Hongbo
中科院分区：
文献类型：
--
作者：
Chen, Lin;Liu, Xiaohong;Zhao, Hongbo
转化酶(Invertase，InVS)在植物生长过程中对环境的响应起着至关重要的作用。以往的工作表明，植物转化酶可以受到小蛋白抑制剂(INVINH)的翻译后调控。在这里，本研究描述了一种玉米InVS的蛋白质类抑制剂(Zm-INVINH4)。对重组蛋白Zm-INVINH4的功能分析表明，它对玉米叶片的细胞壁和液泡转化酶活性均有抑制作用。Zm-INVINH4：：绿色荧光蛋白融合实验表明，该蛋白定位于质外体。转录本分析表明，Zm-INVINH4在玉米的库组织中特异表达，如叶片底部和幼粒。此外，干旱胁迫显著诱导了Zm-INVINH4的表达，并伴随着授粉后第2~7天叶片细胞壁转化酶(CWI)活性的降低和叶片底部蔗糖积累的增加。综上所述，这些结果支持这样的假设，即INV相关的库生长对干旱处理的响应(部分)是通过干旱诱导的Zm-INVINH4蛋白诱导INV活性的沉默引起的。
Invertases (INVs) play essential roles in plant growth in response to environmental cues. Previous work showed that plant invertases can be post-translationally regulated by small protein inhibitors (INVINHs). Here, this study characterizes a proteinaceous inhibitor of INVs in maize (Zm-INVINH4). A functional analysis of the recombinant Zm-INVINH4 protein revealed that it inhibited both cell wall and vacuolar invertase activities from maize leaves. A Zm-INVINH4::green fluorescent protein fusion experiment indicated that this protein localized in the apoplast. Transcript analysis showed that Zm-INVINH4 is specifically expressed in maize sink tissues, such as the base part of the leaves and young kernels. Moreover, drought stress perturbation significantly induced Zm-INVINH4 expression, which was accompanied with a decrease of cell wall invertase (CWI) activities and an increase of sucrose accumulation in both base parts of the leaves 2 to 7 days after pollinated kernels. In summary, the results support the hypothesis that INV-related sink growth in response to drought treatment is (partially) caused by a silencing of INV activity via drought-induced induction of Zm-INVINH4 protein.