Department of Agricultural Sciences, University of Naples Federico II, Portici, Na, Italy.
University of Bordeaux, INRAE, UMR BFP, 33882, Villenave d'Ornon, France.
Plant Physiol Biochem. 2022 May 15;179:32-43. doi: 10.1016/j.plaphy.2022.03.012. Epub 2022 Mar 15.
Drought and heat stresses are the main constrains to agricultural crop production worldwide. Precise and efficient phenotyping is essential to understand the complexity of plant responses to abiotic stresses and to identify the best management strategies to increase plant tolerance. In the present study, two phenotyping platforms were used to investigate the effects of a protein hydrolysate-based biostimulant on the physiological response of two tomato genotypes ('E42' and 'LA3120') subjected to heat, drought, or combined stress. The free amino acids in the biostimulant, or other molecules, stimulated growth in treated plants subjected to combined stress, probably promoting endogenous phytohormonal biosynthesis. Moreover, biostimulant application increased the net photosynthetic rate and maximal efficiency of PSII photochemistry under drought, possibly related to the presence of glycine betaine and aspartic acid in the protein hydrolysate. Increased antioxidant content and a decreased accumulation of hydrogen peroxide, proline, and soluble sugars in treated plants under drought and combined stress further demonstrated that the biostimulant application mitigated the negative effects of abiotic stresses. Generally, the response to biostimulant in plants had a genotype-dependent effect, with 'E42' showing a stronger response to protein hydrolysate application than 'LA3120'. Altogether, in this study a fine and multilevel phenotyping revealed increased plant performances under water-limited conditions and elevated temperatures induced by a protein hydrolysate, thus highlighting the great potential biostimulants have in improving plant resilience to abiotic stresses.
干旱和高温胁迫是全球农业作物生产的主要制约因素。精确和高效的表型分析对于理解植物对非生物胁迫的复杂反应以及确定提高植物耐受性的最佳管理策略至关重要。在本研究中，使用了两种表型分析平台来研究基于蛋白质水解物的生物刺激素对两个番茄基因型（'E42'和'LA3120'）在热、干旱或复合胁迫下的生理响应的影响。生物刺激剂中的游离氨基酸或其他分子可能会刺激复合胁迫下处理过的植物生长，从而促进内源性植物激素的生物合成。此外，生物刺激剂的应用增加了干旱条件下净光合速率和 PSII 光化学最大效率，这可能与蛋白质水解物中存在甘氨酸甜菜碱和天冬氨酸有关。在干旱和复合胁迫下处理过的植物中抗氧化剂含量的增加和过氧化氢、脯氨酸和可溶性糖的积累减少进一步表明，生物刺激剂的应用减轻了非生物胁迫的负面影响。总的来说，生物刺激剂在植物中的响应具有基因型依赖性，'E42'对蛋白质水解物的应用表现出比'LA3120'更强的响应。总之，本研究通过精细和多层次的表型分析，揭示了在蛋白质水解物诱导的水分限制和高温条件下植物性能的提高，从而突出了生物刺激剂在提高植物对非生物胁迫的抗性方面的巨大潜力。
