Disentangling the photosynthesis performance in japonica rice during natural leaf senescence using OJIP fluorescence transient analysis

Abstract

Rice undergoes leaf senescence accompanied with grain filling when the plants reach the end of their temporal niche, and a delay in leaf senescence ultimately improves the yield and quality of grain. To estimate the decline in photosynthesis during leaf senescence and to find an efficient and useful tool to identify rice genotypes with a longer duration of active photosynthesis, we examined PSII photosynthetic activity in the flag leaves of japonica rice Shennong265 (SN265) and Beigeng3 (BG3) during leaf senescence using chlorophyll a fluorescence kinetics. The results show that inhibition occurred in the electron transport chains, but the energetic connectivity of PSII units was not affected as dramatically during leaf senescence. PSII reaction centres (RCs) were transformed into ‘silent RCs,’ and the chlorophyll content decreased during leaf senescence. However the size of the ‘economic’ antennae increased. Further, the percentage of variation of the specific energy flux parameters can rationally be used to indicate leaf senescence from the perspective of energy balance. Although the performance indices were more sensitive than other functional and structural JIP-test parameters, they still did not serve as an indicator of crop yield.

Combining Heat Stress with Pre-Existing Drought Exacerbated the Effects on Chlorophyll Fluorescence Rise Kinetics in Four Contrasting Plant Species

“…This fast tool, based on non-invasive intact measurements, is advantageous in that it reveals multiple components of PSII function with a higher resolution of time-dependent dynamic responses to heat impact during drought stress. OJIP kinetics have been adopted for screening different varieties of crops subjected to heat or drought stress [ 18 , 23 , 24 , 25 , 26 , 27 , 28 ], and for tracing the senescence of rice [ 29 ] and some European oak tree species [ 19 ]. The technique links the different phases of the rise of the fluorescence signal with the redox states of multiple components of photosystem II (PSII) [ 16 , 17 ].…”

Transcriptome and Proteome Analysis Revealed That Hormone and Reactive Oxygen Species Synergetically Regulate Dormancy of Introgression Line in Rice (Oryza sativa L.)

“…The results showed that compared with ZH11, the contents of CAT, POD, and SOD in IL decreased by 46.49, 8.45, and 56.15%, respectively ( Figure 6 B). Notably, the difference in peroxidase content will inevitably lead to a difference in ROS content [ 37 , 38 ]. As expected, compared with ZH11, the content of H 2 O 2 in IL was significantly reduced by 10.55%, but the production rate of O 2 − was significantly increased by 8.39 times ( Figure 6 C,D).…”

Effects of histone methylation modification on low temperature seed germination and growth of maize

“…Low temperature is one of the common abiotic stresses in uences on plant growth, development and yield [46][47][48] . At the late stage of corn powder, the occurrence of low temperature will induce the generation of free radicals in plants, lead to bio lm phase transformation and change the degree of green retention of leaves 49,50 . In the later stage of pollination, higher chlorophyll content in leaves can maintain vigorous through photosynthesis, which is particularly important for improving crop quality and yield 51,52 .…”