High temperature during soybean seed development differentially alters lipid and protein metabolism

Abstract

High temperatures during seed development can affect the seed yield and quality in many crops. Here, we analyzed how high temperature alters the main seed storage compounds (lipid and protein) in soybean. At five days after R5 stage (initial seed filling stage), soybean plants were treated with control (20/20ºC day/night) and high temperature (30/30ºC day/night). After treatment, immature seed was sampled, analyzed for lipid and protein contents and for expression of seed storage compounds related genes. High temperature during seed filling increased lipid content but decreased protein content, associating with yield reduction. It increased the expression of two genes related to seed lipid biosynthesis (GmBCCP2 and GmKAS1) and genes for a lipid biosynthesis regulator (GmWRI1) and its transcription factor (GmDREBL), and decreased the expression of genes related to lipid degradation such as GmACXs. High temperature downregulated genes related to seed storage protein (GmGy1, GmGy2, GmGy4, GmGy5 and Gmβ-conglycinin) and upregulated genes for cysteine and aspartate proteinases. Therefore, high temperature during seed filling preferentially accumulates lipid than protein content in seed, although seed yield reduction was associated with lower seed protein content in soybean. Our study provides insights for further improvements of soybean seed oil under abiotic stress such as heat stress.

The Influence of Seed Production Environment on Seed Development and Quality of Soybean (Glycine max (L.) Merrill)

“…Furthermore, the present study was found to have moderate negative correlations between sucrose and RFOs with EC values of (r = −0.62 **) and (r = −0.67 **), respectively. This result is consistent with several studies [54][55][56] that reported sucrose and RFOs might be involved in membrane stabilization.…”

“…Our findings clearly demonstrated that seed deterioration was further accelerated at P2-POL, P1-ALU, and P2-ALU due to the exposure of more than 400 GDD during the LR stage, and it was mainly due to exceeding the threshold heat limit during that particular period (Table 1). Further, it is in line with a previous study which reported that exposure to high heat and humidity during seed maturation could result in lower seed quality [55].…”

Effect of Heat Stress on Seed Protein Composition and Ultrastructure of Protein Storage Vacuoles in the Cotyledonary Parenchyma Cells of Soybean Genotypes That Are Either Tolerant or Sensitive to Elevated Temperatures

“…However, seeds produced under 42/26 • C day/night temperatures had a noticeable decline in the accumulation of a small number of proteins, with sizes of 94 kDa, 52 kDa, and 14 kDa (Figure 1A). the metabolite profile and gene expression [9,11,12,17]. Since protein is the most important component of soybean seed, a detailed understanding of the effect of heat stress on the accumulation of seed proteins is vital to mitigate the adverse effect of heat stress.…”

“…Soybean seeds of typical lines accumulate 36–40% protein and ~20% oil [ 2 ] and these two important components are stored in specialized structures in soybean seed; protein storage vacuoles (PSV) accumulate seed storage proteins, whereas oil is stored within lipid bodies [ 13 , 14 , 15 ]. While several studies have been conducted on the effect of elevated temperature on the overall oil and protein content of seed [ 12 , 16 , 17 ], only limited information is available on the effect of heat stress on the ultrastructure of the storage organs. Additionally, previous studies that employed omic approaches were focused on global changes in the metabolite profile and gene expression [ 9 , 11 , 12 , 17 ].…”

“…While several studies have been conducted on the effect of elevated temperature on the overall oil and protein content of seed [ 12 , 16 , 17 ], only limited information is available on the effect of heat stress on the ultrastructure of the storage organs. Additionally, previous studies that employed omic approaches were focused on global changes in the metabolite profile and gene expression [ 9 , 11 , 12 , 17 ]. Since protein is the most important component of soybean seed, a detailed understanding of the effect of heat stress on the accumulation of seed proteins is vital to mitigate the adverse effect of heat stress.…”