Casadesús Andrea, Pérez-Llorca Marina, Munné-Bosch Sergi, Polo Javier
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain.
Research Institute of Nutrition and Food Safety (INSA), University of Barcelona, Barcelona, Spain.
Front Plant Sci. 2020 Jul 1;11:953. doi: 10.3389/fpls.2020.00953. eCollection 2020.
Biostimulants may be particularly interesting for application in agricultural and horticultural crops since they can exert a growth-promoting effect on roots. This may be important for promoting longitudinal and lateral root growth and therefore increasing belowground vegetative growth, which may in turn lead to improved aboveground vegetative growth and increased yields. Here, we examined the effects and mechanism of action of an enzymatically hydrolyzed animal protein-based biostimulant (Pepton) on the root growth of tomato plants, with an emphasis on its possible role on chorismate-derived hormones (auxin, salicylic acid, and melatonin). Tomato plants growing in hydroponic systems were exposed to either nutrient stress conditions (experiment 1) or suboptimal temperatures (experiment 2) in a greenhouse, and the concentration of auxin, salicylic acid, and melatonin in roots were measured just prior and after the application of the biostimulant. Results showed that the application of Pepton exerted a growth-promoting effect on roots in plants growing under suboptimal conditions, which might be associated with enhanced salicylic acid levels in roots. The extent of effects of this enzymatically hydrolyzed animal protein-based biostimulant might strongly depend on the growth conditions and stage of root system development. It is concluded that an enzymatically hydrolyzed animal protein-based biostimulant (Pepton) may exert a positive effect enhancing primary and lateral root growth of tomato plants growing under suboptimal conditions, by stimulating the biosynthesis of specific hormonal pathways, such as salicylic acid under stress.
生物刺激素在农业和园艺作物中的应用可能特别有趣，因为它们可以对根系产生促生长作用。这对于促进主根和侧根生长从而增加地下营养生长可能很重要，而这反过来可能会导致地上营养生长改善和产量增加。在此，我们研究了一种基于酶解动物蛋白的生物刺激素（蛋白胨）对番茄植株根系生长的影响及其作用机制，重点关注其在分支酸衍生激素（生长素、水杨酸和褪黑素）方面可能发挥的作用。在温室水培系统中生长的番茄植株，在实验1中处于营养胁迫条件下，在实验2中处于次优温度条件下，在施用生物刺激素之前和之后测量根系中生长素、水杨酸和褪黑素的浓度。结果表明，蛋白胨的施用对处于次优条件下生长的植株根系有促生长作用，这可能与根系中水杨酸水平的提高有关。这种基于酶解动物蛋白的生物刺激素的作用程度可能很大程度上取决于生长条件和根系发育阶段。得出的结论是，一种基于酶解动物蛋白的生物刺激素（蛋白胨）可能通过刺激特定激素途径的生物合成，如在胁迫下刺激水杨酸的合成，对处于次优条件下生长的番茄植株主根和侧根的生长发挥积极作用。
