Cui Xuelian, He Wen, Christensen Michael John, Yue Jinfeng, Zeng Fanbin, Zhang Xingxu, Nan Zhibiao, Xia Chao
The State Key Laboratory of Herbage Seeds and Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China.
AgResearch Limited, Grasslands Research Centre, Palmerston North 4442, New Zealand.
J Fungi (Basel). 2022 Oct 28;8(11):1140. doi: 10.3390/jof8111140.
Water scarcity is a major constraint that adversely affects plant development and growth. Abscisic acid (ABA) is a plant stress hormone that is rapidly synthesized and can induce stomatal closure to conserve water, thereby alleviating the drought stress of plants. The endophyte enhances the drought tolerance of (drunken horse grass, DHG). To better understand how the endophyte enhances drought tolerance, DHG plants without (EF) and with (EI), an endophyte, were grown under 20% and 60% soil water conditions (SWC), and the leaves of the three treatments of EF and EI plants were sprayed with ABA solution (1 mg/L); fluridone (FLU), the ABA biosynthesis inhibitor solution (1 mg/L); and distilled water, respectively. Four-weeks later, the results indicated that the exogenous ABA application promoted plant growth, stomatal conductance, and photosynthetic rate, while the opposite effect occurred with plants sprayed with FLU. The differences between EI and EF plants in tiller number, height, chlorophyll content, stomata conductance, and photosynthetic rate were highest when sprayed with ABA. Thus, it is concluded that ABA might be involved in the moderating effect of endophytes on DHG plants exposed to drought by maintaining growth and improving photosynthetic efficiency.
水资源短缺是一个严重制约因素，对植物的发育和生长产生不利影响。脱落酸（ABA）是一种植物应激激素，能迅速合成并诱导气孔关闭以保存水分，从而减轻植物的干旱胁迫。内生菌可提高醉马草（DHG）的耐旱性。为了更好地了解内生菌如何提高耐旱性，在20%和60%土壤水分条件（SWC）下种植不含内生菌（EF）和含内生菌（EI）的DHG植株，对EF和EI植株的三种处理的叶片分别喷施ABA溶液（1毫克/升）、ABA生物合成抑制剂氟啶酮（FLU）溶液（1毫克/升）和蒸馏水。四周后，结果表明，外源ABA处理促进了植物生长、气孔导度和光合速率，而喷施FLU的植株则出现相反效果。喷施ABA时，EI和EF植株在分蘖数、株高、叶绿素含量、气孔导度和光合速率方面的差异最大。因此得出结论，ABA可能通过维持生长和提高光合效率，参与内生菌对遭受干旱的DHG植株的调节作用。
