Abstract

In this study, we chose apple leaf as plant material and studied effects of GeO2 on operation of photosynthetic apparatus and antioxidant enzyme activities under strong light. When exogenous GeO2 concentration was below 5.0 mg L–1, maximum photochemical quantum yield of PSII and actual quantum yield of PSII photochemistry increased significantly compared with the control under irradiances of 800 and 1,600 μmol(photon) m–2 s–1. Photosynthetic electron transport chain capacity between QA–QB, QA–PSI acceptor, and QB–PSI acceptor showed a trend of rising up with 1.0, 2.0, and 5.0 mg(GeO2) L–1 and declining with 10.0 mg(GeO2) L–1. On the other hand, dissipated energy via both ΔpH and xanthophyll cycle decreased remarkably compared with the control when GeO2 concentration was below 5.0 mg L–1. Our results suggested that low concentrations of GeO2 could alleviate photoinhibition and 5.0 mg(GeO2) L–1 was the most effective. In addition, we found, owing to exogenous GeO2 treatment, that the main form of this element in apple leaves was organic germanium, which means chemical conversion of germanium happened. The organic germanium might be helpful to allay photoinhibition due to its function of scavenging free radicals and lowering accumulation of reactive oxygen species, which was proven by higher antioxidant enzyme activities.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.