MCA1 and MCA2 Are Involved in the Response to Hypergravity in Arabidopsis Hypocotyls
MCA1 and MCA2 Are Involved in the Response to Hypergravity in Arabidopsis Hypocotyls
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DOI：
10.3390/plants9050590
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发表时间：
2020-05-01
期刊：
影响因子：
4.5
通讯作者：
Hoson, Takayuki
中科院分区：
文献类型：
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作者：
Hattori, Takayuki;Otomi, Yasuhiro;Hoson, Takayuki
植物对重力加速度有反应并能抵抗重力加速度，但这种反应中的信号感知机制尚不清楚。我们研究了MCA（mid 1-互补活性）蛋白在重力感知中的作用，通过分析MCA 1和MCA 2基因的表达，以及MCA突变体下胚轴的生长，在超重力条件下在黑暗中。MCA 1启动子：：GUS融合报告基因构建体（MCA 1 p：：GUS）和MCA 2 p：：GUS在黄化幼苗中几乎普遍表达。在超重力条件下，这两个基因的表达水平均比1g条件下有所增加，并保持较高水平，尤其是在基底支撑区。另一方面，MCA-无效和MCA-过表达的幼苗显示正常的生长在1克的条件下。超重力抑制下胚轴的伸长生长，但与野生型相比，这种影响在mca缺失突变体的下胚轴中减少。与此相反，MCA过表达的幼苗是超敏感的重力增加，抑制伸长生长检测到在较低的重力水平比野生型。这些结果表明，MCAs参与植物对重力信号的感知，并可能负责抵抗超重力。
Plants respond to and resist gravitational acceleration, but the mechanism of signal perception in the response is unknown. We studied the role of MCA (mid1-complementing activity) proteins in gravity perception by analyzing the expression of the MCA1 and MCA2 genes, and the growth of hypocotyls of mca mutants, under hypergravity conditions in the dark. An MCA1 promoter::GUS fusion reporter gene construct (MCA1p::GUS) and MCA2p::GUS were expressed almost universally in etiolated seedlings. Under hypergravity conditions, the expression levels of both genes increased compared with that under the 1 g condition, and remained higher, especially in the basal supporting region. On the other hand, mca-null and MCA-overexpressing seedlings showed normal growth under the 1 g condition. Hypergravity suppressed elongation growth of hypocotyls, but this effect was reduced in hypocotyls of mca-null mutants compared with the wild type. In contrast, MCA-overexpressing seedlings were hypersensitive to increased gravity; suppression of elongation growth was detected at a lower gravity level than that in the wild type. These results suggest that MCAs are involved in the perception of gravity signals in plants, and may be responsible for resistance to hypergravity.