Journal Article

Low red/far-red ratio as a signal promotes carbon assimilation of soybean seedlings by increasing the photosynthetic capacity

Wang, Xiaochun, Du, Junbo, Cheng, Yajiao, Liu, Weiguo, Shu, Kai, Liu, Jiang, Raza, Muhammad Ali, Yong, Taiwen, Yang, Wenyu, Wu, Xiaoling, Liu, Qinlin, Yang, Feng, Feng, Lingyang, Fan, Yuanfang

2020

Overview

Background Shading includes low light intensity and varying quality. However, a low red/far-red (R/Fr) ratio of light is a signal that affects plant growth in intercropping and close- planting systems. Thus, the low R/Fr ratio uncoupling from shading conditions was assessed to identify the effect of light quality on photosynthesis and CO 2 assimilation. Soybean plants were grown in a growth chamber with natural solar radiation under four treatments, that is, normal (N, sunlight), N + Fr, Low (L) + Fr, and L light. Results Low R/Fr ratio significantly increased the total biomass, leaf area, starch and sucrose contents, chlorophyll content, net photosynthetic rate, and quantum efficiency of the photosystem II compared with normal R/Fr ratio under the same light level ( P  < 0.05). Proteomic analysis of soybean leaves under different treatments was performed to quantify the changes in photosynthesis and CO 2 assimilation in the chloroplast. Among the 7834 proteins quantified, 12 showed a > 1.3-fold change in abundance, of which 1 was related to porphyrin and chlorophyll metabolism, 2 were involved in photosystem I (PS I), 4 were associated with PS II, 3 proteins participated in photosynthetic electron transport, and 2 were involved in starch and sucrose metabolism. The dynamic change in these proteins indicates that photosynthesis and CO 2 assimilation were maintained in the L treatment by up-regulating the component protein levels compared with those in N treatment. Although low R/Fr ratio increased the photosynthetic CO 2 assimilation parameters, the differences in most protein expression levels in N + Fr and L + Fr treatments compared with those in N treatment were insignificant. Similar trends were found in gene expression through quantitative reverse transcription polymerase chain reaction excluding the gene expression of sucrose synthase possible because light environment is one of the factors affecting carbon assimilation. Conclusions Low R/Fr ratio (high Fr light) can increase the photosynthetic CO 2 assimilation in the same light intensity by improving the photosynthetic efficiency of the photosystems.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agricultural practices / Agricultural production / Agriculture / Analysis / Assimilation / Biological assimilation / Biomass / Biomedical and Life Sciences / Carbon dioxide / carbon dioxide fixation / Chlorophyll / Chloroplasts / Chloroplasts - radiation effects / Chloroplasts - ultrastructure / CO2 assimilation / Cropping systems / Electron transport / Gene expression / Glycine max - growth & development / Glycine max - metabolism / Glycine max - radiation effects / Glycine max - ultrastructure / Growth chambers / Intercropping / Leaf area / Leaves / Life Sciences / Light / Light intensity / Light levels / Light quality / Luminous intensity / Photosynthesis / Photosynthesis - radiation effects / photosynthetic electron transport / Photosystem I / Photosystem II / Physiological aspects / Physiology / Plant biochemistry / Plant growth / Plant Sciences / Plant-abiotic interactions / Polymerase chain reaction / protein synthesis / Proteins / Proteome / Proteomics / Quantum efficiency / Radiation (Physics) / Research Article / reverse transcriptase polymerase chain reaction / Reverse transcription / Scientific equipment industry / Seedlings / Seedlings - metabolism / Seedlings - radiation effects / Shade / Shading / Solar radiation / Soybean / Soybeans / Starch / Statistics / Sucrose / Sucrose synthase / Sugar / Tree Biology / Trends