Sun Shuangsheng, Yang Zhengkun, Song Zhiyu, Wang Nannan, Guo Ning, Niu Jinghan, Liu Airong, Bai Bing, Ahammed Golam Jalal, Chen Shuangchen
College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang, China.
Wageningen Seed Science Centre, Laboratory of Plant Physiology, Wageningen University, Wageningen, Netherlands.
Front Plant Sci. 2022 Oct 13;13:1011859. doi: 10.3389/fpls.2022.1011859. eCollection 2022.
wilt, caused by f. sp. (Fo), is a severe soil-borne disease affecting cucumber production worldwide, particularly under monocropping in greenhouses. Silicon (Si) plays an important role in improving the resistance of crops to wilt, but the underlying mechanism is largely unclear. Here, an study showed that 3 mmol·l Si had the best inhibitory effect on the mycelial growth of in potato dextrose agar (PDA) culture for 7 days. Subsequently, the occurrence of cucumber wilt disease and its mechanisms were investigated upon treatments with exogenous silicon under soil culture. The plant height, stem diameter, root length, and root activity under Si+Fo treatment increased significantly by 39.53%, 94.87%, 74.32%, and 95.11% compared with Fo only. Importantly, the control efficiency of Si+Fo was 69.31% compared with that of Fo treatment. Compared with Fo, the activities of peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) significantly increased by 148.92%, 26.47%, and 58.54%, while the contents of HO, , and malondialdehyde (MDA) notably decreased by 21.67%, 59.67%, and 38.701%, respectively, in roots of cucumber plants treated with Si + Fo. Compared with Fo treatment, the net photosynthesis rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum RuBisCO carboxylation rates (cmax), maximum RuBP regeneration rates (max), and activities of ribulose-1,5-bisphosphate carboxylase (RuBisCO), fructose-1,6-bisphosphatase (FBPase), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the expression of , , , and in Si+Fo treatment increased significantly. Furthermore, Si alleviated stomatal closure and enhanced endogenous silicon content compared with only Fo inoculation. The study results suggest that exogenous silicon application improves cucumber resistance to wilt by stimulating the antioxidant system, photosynthetic capacity, and stomatal movement in cucumber leaves. This study brings new insights into the potential of Si application in boosting cucumber resistance against wilt with a bright prospect for Si use in cucumber production under greenhouse conditions.
由尖孢镰刀菌黄瓜专化型（Fo）引起的枯萎病是一种严重的土传病害，影响着全球黄瓜生产，尤其是在温室单作种植条件下。硅（Si）在提高作物对枯萎病的抗性方面发挥着重要作用，但其潜在机制在很大程度上尚不清楚。在此，一项研究表明，在马铃薯葡萄糖琼脂（PDA）培养基中培养7天时，3 mmol·l的硅对Fo的菌丝生长具有最佳抑制作用。随后，在土壤培养条件下，对外源硅处理后的黄瓜枯萎病发生情况及其机制进行了研究。与仅接种Fo相比，Si+Fo处理下的黄瓜株高、茎粗、根长和根系活力分别显著增加了39.53%、94.87%、74.32%和95.11%。重要的是，与Fo处理相比，Si+Fo的防治效果为69.31%。与Fo相比，在Si+Fo处理的黄瓜植株根系中，过氧化物酶（POD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的活性分别显著提高了148.92%、26.47%和58.54%，而羟基自由基（HO·）、超氧阴离子（O₂⁻）和丙二醛（MDA）的含量则分别显著降低了21.67%、59.67%和38.70%。与Fo处理相比，Si+Fo处理下的净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）、最大羧化速率（cmax）、最大RuBP再生速率（Jmax）、1,5-二磷酸核酮糖羧化酶（RuBisCO）、果糖-1,6-二磷酸酶（FBPase）和甘油醛-3-磷酸脱氢酶（GAPDH）的活性以及相关基因的表达均显著增加。此外，与仅接种Fo相比，硅缓解了气孔关闭并提高了内源硅含量。研究结果表明，外源施硅通过刺激黄瓜叶片的抗氧化系统、光合能力和气孔运动来提高黄瓜对枯萎病的抗性。本研究为施硅提高黄瓜对枯萎病的抗性潜力带来了新的见解，为温室条件下黄瓜生产中硅的应用提供了广阔前景。
