<institution content-type="university">Instituto de Investigaciones en Ingeniería Genética y Biología Molecular 'Dr. Héctor N. Torres' (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Vuelta de Obligado 2490</institution>, <city>Buenos Aires</city>, <country>Argentina</country>.
<institution content-type="university">Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental and Instituto de Biodiversidad y Biología Experimental Aplicada (IBBEA), Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Int. Güiraldes y Cantilo</institution>, <city>Buenos Aires</city>, <country>Argentina</country>.
Funct Plant Biol. 2023 Dec;50(12):1117-1129. doi: 10.1071/FP23163.
In this study, agronomic and functional characteristics of potato (Solanum tuberosum ) plants constitutively overexpressing the protein phosphatase 2A (PP2A) catalytic subunit StPP2Ac2b (StPP2Ac2b-OE) were evaluated. StPP2Ac2b-OE plants display reduced vegetative growth, tuber yield and tuber weight under well-watered and drought conditions. Leaves of StPP2Ac2b-OE plants show an increased rate of water loss, associated with an impaired ability to close stomata in response to abscisic acid. StPP2Ac2b-OE lines exhibit larger stomatal size and reduced stomatal density. These altered stomatal characteristics might be responsible for the impaired stomatal closure and the elevated transpiration rates, ultimately leading to increased sensitivity to water-deficit stress and greater yield loss under drought conditions. Overexpression of StPP2Ac2b accelerates senescence in response to water-deficit stress, which could also contribute to the increased sensitivity to drought. Actively photosynthesising leaves of StPP2Ac2b-OE plants exhibit elevated levels of carbohydrates and a down-regulation of the sucrose transporter StSWEET11 , suggesting a reduced sucrose export from leaves to developing tubers. This effect, combined with the hindered vegetative development, may contribute to the reduced tuber weight and yield in StPP2Ac2b-OE plants. These findings offer novel insights into the physiological functions of PP2A in potato plants and provide valuable information for enhancing potato productivity by modulating the expression of StPP2Ac2b .
本研究评估了组成型过表达蛋白磷酸酶 2A（PP2A）催化亚基 StPP2Ac2b（StPP2Ac2b-OE）的马铃薯（Solanum tuberosum）植株的农艺和功能特性。在充分供水和干旱条件下，StPP2Ac2b-OE 植株的营养生长、块茎产量和块茎重量均降低。StPP2Ac2b-OE 植株叶片的失水率增加，与 ABA 响应中关闭气孔的能力受损有关。StPP2Ac2b-OE 系的气孔较大，气孔密度降低。这些改变的气孔特征可能是气孔关闭受损和蒸腾速率升高的原因，最终导致对水分胁迫的敏感性增加和干旱条件下产量损失更大。StPP2Ac2b 的过表达加速了对水分胁迫的衰老，这也可能导致对干旱的敏感性增加。StPP2Ac2b-OE 植株正在积极进行光合作用的叶片表现出较高水平的碳水化合物和蔗糖转运蛋白 StSWEET11 的下调，表明从叶片到发育中的块茎的蔗糖输出减少。这种效应，加上营养生长受阻，可能导致 StPP2Ac2b-OE 植株的块茎重量和产量降低。这些发现为 PP2A 在马铃薯植株中的生理功能提供了新的见解，并为通过调节 StPP2Ac2b 的表达来提高马铃薯生产力提供了有价值的信息。
