Soybean (Glycine max L. Merr.) seedlings response to shading: leaf structure, photosynthesis and proteomic analysis

Abstract

BackgroundIntercropping and close planting are important cultivation methods that increase soybean yield in agricultural production. However, plant shading is a major abiotic stress factor that influences soybean growth and development. Although shade affects leaf morphological parameters and decreases leaf photosynthesis capacity, information on the responses of soybean leaf photosynthesis to shading at proteomic level is still lacking.ResultsCompared with leaves under normal light (CK) treatment, leaves under shading treatment exhibited decreased palisade and spongy tissue thicknesses but significantly increased cell gap. Although shade increased the number of the chloroplast, the thickness of the grana lamella and the photosynthetic pigments per unit mass, but the size of the chloroplast and starch grains and the rate of net photosynthesis decreased compared with those of under CK treatment. A total of 248 differentially expressed proteins, among which 138 were upregulated, and 110 were downregulated, in soybean leaves under shading and CK treatments were detected via isobaric tags for relative and absolute quantification labeling in the three biological repeats. Differentially expressed proteins were classified into 3 large and 20 small groups. Most proteins involved in porphyrin and chlorophyll metabolism, photosynthesis-antenna proteins and carbon fixation in photosynthetic organisms were upregulated. By contrast, proteins involved in photosynthesis were downregulated. The gene family members corresponding to differentially expressed proteins, including protochlorophyllide reductase (Glyma06g247100), geranylgeranyl hydrogenase (Ggh), LHCB1 (Lhcb1) and ferredoxin (N/A) involved in the porphyrin and chlorophyll metabolism, photosynthesis-antenna proteins and photosynthesis pathway were verified with real-time qPCR. The results showed that the expression patterns of the genes were consistent with the expression patterns of the corresponding proteins.ConclusionsThis study combined the variation of the soybean leaf structure and differentially expressed proteins of soybean leaves under shading. These results demonstrated that shade condition increased the light capture efficiency of photosystem II (PSII) in soybean leaves but decreased the capacity from PSII transmitted to photosystem II (PSI). This maybe the major reason that the photosynthetic capacity was decreased in shading.Electronic supplementary materialThe online version of this article (10.1186/s12870-019-1633-1) contains supplementary material, which is available to authorized users.

Genome-wide identification of GRF transcription factors in soybean and expression analysis of GmGRF family under shade stress

“…For example, when exposed to shade stress from neighboring plants, plants adapted to open ranges (e.g. Arabidopsis, rice and soybean) can develop shade avoidance response, leading to shade avoidance syndrome [60][61][62]. Shade avoidance response is conducive to survival of the plant under shade conditions [61,63].…”

Effects of light intensity on the growth, photosynthetic characteristics, and secondary metabolites of Eleutherococcus senticosus Harms

“…The effects of environmental stress on photosynthesis of medicinal plants include regulating the stomatal size and causing damage to the PSII reaction center (Berry and Downton 1982). Previous studies showed that the effects of shading conditions on photosynthesis of different medicinal plants were different (Wang et al 2017, Tafoya et al 2018, Fan et al 2019.…”

Nutritional Composition, Bioactive Compounds and Functional Evaluation of Various Parts of Cajanus cajan (L.) Millsp

“…[21]. Previous studied have reported that sprouts, leaves and seeds of soybean and mung bean contain high amounts of crude proteins, amino acids, lipids and minerals [22][23][24]. They have been shown to possess antioxidant, antimicrobial, anti-inflammatory, antidiabetic and antihypertensive effects [23].…”