Wang Chang, Liu Zhe, Wang Zicheng, Pang Wenhui, Zhang Long, Wen Zhaozhu, Zhao Yiran, Sun Juan, Wang Zeng-Yu, Yang Chao
Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, College of Grassland Science, Qingdao Agricultural University, Qingdao, China.
Front Plant Sci. 2022 Jul 15;13:908426. doi: 10.3389/fpls.2022.908426. eCollection 2022.
Autotoxicity is a form of intraspecific allelopathy, in which a plant species inhibits the establishment or growth of the same species through the release of toxic chemical compounds into the environment. The phenomenon of autotoxicity in crops is best traced in alfalfa (). A close relative of alfalfa, has been developed into an excellent model species for leguminous plants. However, it is not known whether has autotoxicity. In this study, root exudates showed a negative impact on the growth of seedlings, indicating autotoxicity. Detailed analyses with plant extracts from and alfalfa revealed varying degrees of suppression effects in the two species. The extracts negatively affected seed germination potential, germination rate, radicle length, hypocotyl length, synthetic allelopathic effect index, plant height, root growth, fresh weight, dry weight, net photosynthetic rate, transpiration rate, and stomatal conductance in both and alfalfa. The results demonstrated that autotoxicity and allelopathic effects exist in . This opens up a new way to use as a model species to carry out in-depth studies of autotoxicity and allelopathy to elucidate biochemical pathways of allelochemicals and molecular networks controlling biosynthesis of the chemicals.
自毒作用是种内化感作用的一种形式，即植物物种通过向环境中释放有毒化合物来抑制同一物种的定殖或生长。作物中的自毒作用现象在苜蓿中最为明显。苜蓿的一个近缘种已被培育成为豆科植物的优良模式物种。然而，尚不清楚该近缘种是否具有自毒作用。在本研究中，该近缘种的根系分泌物对苜蓿幼苗的生长产生了负面影响，表明存在自毒作用。对该近缘种和苜蓿的植物提取物进行的详细分析显示，这两个物种存在不同程度的抑制作用。提取物对苜蓿和该近缘种的种子萌发潜力、发芽率、胚根长度、下胚轴长度、综合化感效应指数、株高、根系生长、鲜重、干重、净光合速率、蒸腾速率和气孔导度均产生了负面影响。结果表明该近缘种存在自毒作用和化感效应。这为将该近缘种用作模式物种来深入研究自毒作用和化感作用开辟了一条新途径，以阐明化感物质的生化途径以及控制这些化学物质生物合成的分子网络。
