Biology Division, Indian Institute of Science Education and Research (IISER Pune), Pune, India.
Plant Signal Behav. 2020 May 3;15(5):1744373. doi: 10.1080/15592324.2020.1744373. Epub 2020 Apr 1.
Leaf development is a complex process and factors such as size, shape, curvature, compounding, and texture determine the final leaf morphology. MicroRNA160 is one of the crucial players that has been shown to regulate lamina formation and compounding in tomato. In this study, we show that miR160 also regulates leaf curvature in potato. miR160 targets a group of Auxin Response Factors - , and that are proposed to function majorly as repressors of auxin signaling. We observed that overexpression of miR160 (miR160-OE) results in decrease in the levels of these ARFs along with hypersensitivity to exogenous auxin treatment, whereas knockdown of miR160 (miR160-KD) causes increased ARF levels and auxin hyposensitivity. The leaves of miR160-OE plants have a high positive curvature, but of miR160-KD plants are flattened compared to wildtype. A prolonged activation of cell cycle - as indicated by increased levels of - in the center region of miR160-OE leaves appears to have caused this positive curvature. However, a comparable activity at both center and margin regions of miR160-KD leaves could be the cause for its flattened leaf phenotype. In summary, we show that miR160 plays an important role in regulating leaf curvature in potato plants.
叶片发育是一个复杂的过程，大小、形状、曲率、复叶和质地等因素决定了最终的叶片形态。miR160 是调控番茄叶片形成和复叶的关键因子之一。在本研究中，我们表明 miR160 也调控马铃薯叶片的曲率。miR160 靶向一组生长素响应因子（Auxin Response Factors，ARFs），这些因子被认为主要作为生长素信号的抑制剂发挥作用。我们观察到，过表达 miR160（miR160-OE）会导致这些 ARF 水平降低，对外源生长素处理表现出超敏反应，而 miR160 的敲低（miR160-KD）会导致 ARF 水平升高和生长素低敏性。miR160-OE 植株的叶片具有高的正曲率，但 miR160-KD 植株的叶片与野生型相比则较平。miR160-OE 叶片中心区域细胞周期的延长激活——表现为 水平升高——似乎导致了这种正曲率。然而，miR160-KD 叶片中心和边缘区域的类似 活性可能是其叶片平坦表型的原因。总之，我们表明 miR160 在调控马铃薯叶片曲率中起着重要作用。
