Shandong Academy of Forestry, 42, East Wenhua Road, Jinan, 250014, Shandong, China.
Economic Forest Products Quality Inspection Test Center of State Forestry Administration (Jinan), Jinan, 250014, Shandong, China.
Appl Microbiol Biotechnol. 2021 Dec;105(23):8951-8968. doi: 10.1007/s00253-021-11653-9. Epub 2021 Nov 4.
Juglans regia L. is a good host for Serendipita indica. Under drought condition, seedlings colonized with S. indica showed higher values in plant height, total fresh biomass, root/shoot ratio, relative growth rate, leaf relative water content and chlorophyll content, gas exchange parameters, maximal photochemical efficiency, photochemical quenching, and effective photosystem II quantum yield than the uncolonized seedlings. It suggested beneficial effects of S. indica on host plants' growth and physiological parameters in response to drought. In comparison with the uncolonized seedlings, S. indica-colonized seedlings showed lower levels in hydrogen peroxide, superoxide anion, malondialdehyde, and relative electrical conductivity under drought condition, suggesting the ability of S. indica to prevent or retard the accumulation of reactive oxygen species and to diminish the oxidative injure. Furthermore, walnut seedlings responded to drought by actively accumulating osmotic regulation substances including soluble protein, soluble sugar, and proline. Root colonization with S. indica was more conductive to the accumulation. Moreover, in response to drought stress, walnut seedlings, regardless of colonization, increased activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione reductase, levels of ascorbate and glutathione, and ratios of reduced ascorbate/dehydroascorbic acid and reduced glutathione/oxidized glutathione in leaves and roots. S. indica colonization induced much more increase in the abovementioned indicators as compared to the uncolonized seedlings. Overall, S. indica colonization alleviated the detrimental effects of drought stress by altering root system, enhancing osmotic adjustment, and repressing the accumulation of reactive oxygen species via stimulating antioxidant system including enzymatic and nonenzymatic components. KEY POINTS: • S. indica stimulated root growth of walnut seedlings under drought condition. • S. indica accelerated osmotic adjustment under drought condition. • S. indica activated antioxidant defense mechanism under drought condition.
欧洲榛是被孢霉的良好宿主。在干旱条件下，被被孢霉定殖的实生苗在株高、总鲜重、根/冠比、相对生长率、叶片相对含水量和叶绿素含量、气体交换参数、最大光化学效率、光化学猝灭、有效光系统 II 量子产量方面表现出更高的值，比未定殖的实生苗。这表明被孢霉对宿主植物的生长和生理参数在应对干旱方面有有益的影响。与未定殖的实生苗相比，在干旱条件下，被被孢霉定殖的实生苗的过氧化氢、超氧阴离子、丙二醛和相对电导率水平较低，表明被孢霉具有防止或延缓活性氧积累和减少氧化损伤的能力。此外，核桃实生苗通过积极积累渗透调节物质（包括可溶性蛋白、可溶性糖和脯氨酸）来应对干旱。被被孢霉定殖更有利于积累。此外，在应对干旱胁迫时，无论是否被定殖，核桃实生苗都会增加叶片和根系中超氧化物歧化酶、过氧化氢酶、过氧化物酶、抗坏血酸过氧化物酶、脱氢抗坏血酸还原酶、单脱氢抗坏血酸还原酶、谷胱甘肽还原酶、抗坏血酸和谷胱甘肽的水平，以及还原型抗坏血酸/脱氢抗坏血酸和还原型谷胱甘肽/氧化型谷胱甘肽的比例。与未定殖的实生苗相比，被孢霉定殖诱导了上述指标的更大增加。总体而言，被孢霉通过改变根系、增强渗透调节和抑制活性氧积累，通过刺激包括酶和非酶成分在内的抗氧化防御系统，缓解干旱胁迫的不利影响。关键点：• 被孢霉在干旱条件下刺激核桃实生苗的根系生长。• 被孢霉在干旱条件下加速渗透调节。• 被孢霉在干旱条件下激活抗氧化防御机制。
