高生长温度对大豆产生负面影响(甘氨酸max(L.)Merr)产量和种子质量。大豆植物,种子发育过程中的热胁迫,产生表现出皱纹的种子,变色,种子发芽不良,病原体感染的可能性增加,经济价值总体下降。大豆育种者已经确定了一种耐受热胁迫的外来地方品种基因型,在传统杂交中用于产生实验基因型,提高了种子产量和耐热性。这里,我们研究了对高生长温度敏感或耐受的大豆基因型子叶薄壁组织细胞的种子蛋白质组成和超微结构。从28/22°C(对照)下产生的耐热和热敏基因型中分离出的种子蛋白的生化分析,36/24°C(中度),和42/26°C(极端)昼夜温度表明,大豆种子中脂加氧酶的积累,β-伴大豆球蛋白的β亚基,蔗糖结合蛋白和Bowman-Birk蛋白酶抑制剂在两种基因型中都受到极端热应激的负面影响,但这些影响在耐热基因型中不太明显。Western印迹分析显示,在种子灌浆过程中,由于温度升高,两系中热休克蛋白(HSP70和HSP17.6)的积累都升高。透射电子显微镜显示,热应激导致储存薄壁组织细胞发生剧烈的结构变化。极端热应激破坏了蛋白质储存液泡的结构和膜完整性,积累种子储存蛋白的细胞器。在敏感系的细胞中通常观察到质膜与细胞壁的分离(质解)。相比之下,这些结构变化在耐受性基因型中不太明显,即使在极端的热应力下,细胞,在大多数情况下,保持其结构完整性。我们的研究结果表明,热应激对种子蛋白质组成和超微结构改变的对比影响,这有助于耐受基因型在种子发育过程中耐受高温的能力。
High growth temperatures negatively affect soybean (Glycine max (L.) Merr) yields and seed quality. Soybean plants, heat stressed during seed development, produce seed that exhibit wrinkling, discoloration, poor seed germination, and have an increased potential for incidence of pathogen infection and an overall decrease in economic value. Soybean breeders have identified a heat stress tolerant exotic landrace genotype, which has been used in traditional hybridization to generate experimental genotypes, with improved seed yield and heat tolerance. Here, we have investigated the seed protein composition and ultrastructure of cotyledonary parenchyma cells of soybean genotypes that are either susceptible or tolerant to high growth temperatures. Biochemical analyses of seed proteins isolated from heat-tolerant and heat-sensitive genotypes produced under 28/22 °C (control), 36/24 °C (moderate), and 42/26 °C (extreme) day/night temperatures revealed that the accumulation in soybean seeds of lipoxygenase, the β-subunit of β-conglycinin, sucrose binding protein and Bowman-Birk protease inhibitor were negatively impacted by extreme heat stress in both genotypes, but these effects were less pronounced in the heat-tolerant genotype. Western blot analysis showed elevated accumulation of heat shock proteins (HSP70 and HSP17.6) in both lines in response to elevated temperatures during seed fill. Transmission electron microscopy showed that heat stress caused dramatic structural changes in the storage parenchyma cells. Extreme heat stress disrupted the structure and the membrane integrity of protein storage vacuoles, organelles that accumulate seed storage proteins. The detachment of the plasma membrane from the cell wall (plasmolysis) was commonly observed in the cells of the sensitive line. In contrast, these structural changes were less pronounced in the tolerant genotype, even under extreme heat stress, cells, for the most part, retained their structural integrity. The results of our study demonstrate the contrasting effects of heat stress on the seed protein composition and ultrastructural alterations that contribute to the tolerant genotype\'s ability to tolerate high temperatures during seed development.