Effect of phosphorus deficiency on the photosynthetic characteristics of rice plants

作者：Hong Xu, X. Y. Weng, Yuting Yang · 发表于：Russian Journal of Plant Physiology · 年份：2007 · DOI：10.1134/s1021443707060040 · 被引用次数：140 · 研究领域：Photosynthetic Processes and Mechanisms、Plant Stress Responses and Tolerance、Plant Micronutrient Interactions and Effects

The effects of phosphorus deficiency on the photosynthetic characteristics were studied in rice seedlings (Oryza sativa L.) every 8 days after treatment. P deficiency caused a significant reduction in the net photosynthesis rate (P N) in rice plants. During the first 16 days of P deficiency, the maximum efficiency of PSII photochemistry (F v/F m), the effective PSII quantum yield (ϕPSII), the electron transport rate (ETR) as well as photochemical quenching (qP) in the P-limited rice plants kept close to the control, but the excitation energy capture efficiency of PSII reaction centers (F′v/F′m) was significantly declined in the P-deficient rice leaves. Meanwhile, in the stressed leaves, we also found a significant increase in nonphotochemical quenching (NPQ) as well as in the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). It was indicated that a series of photoprotective mechanisms had been initiated in rice plants in response to short-term P deficiency. Therefore, PSII functioning was not affected significantly under such stress. As P deficiency continued, the excess excitation energy was accumulated in excess of the capacity of photoprotection systems. When the rice suffered from P deficiency more than 16 days, ϕPSII, ETR, and qP were decreased more rapidly than that in the control plants, although NPQ still kept higher in the stressed plants. These results were also consistent with the data on the distribution of excitation energy. The excess ener...