菜豆豆荚发育过程中内源激素与细胞壁代谢的关系

细胞壁代谢严重影响鲜食菜豆(PhaseolusvulgarisL.)的食用品质。以‘大白棒’豆荚为试材,研究其4个发育阶段内源激素含量、细胞壁主要成分及酶活性的变化,并分析其内源激素与细胞壁代谢的关系。结果表明,豆荚发育过程中GA₃和6-BA含量呈下降趋势,乙烯(ET)生成速率和茉莉酸(JA)含量呈先降后增趋势;豆荚在花后前10d以增长为主,花后10d后以增粗为主;花后前10d蔗糖合成酶(SuSy)促进蔗糖合成,随着SuSy活性和纤维素酶(Cx)活性的下降,蔗糖含量降低,纤维素含量升高;花后5 d时G木质素在木质部沉积,花后10 d时G木质素和S木质素均在韧皮部沉积,逐渐增多并向两边扩散,S木质素仅在韧皮部沉积;花后5 d时苯丙氨酸解氨酶(PAL)活性高,为木质素生物合成提供底物,随后肉桂醇脱氢酶(CAD)活性增加,促进木质素合成;超氧化物歧化酶(SOD)活性增加促进O2^-向H₂O₂转化,与增加的过氧化物酶(POD)催化木质素的氧化聚合;多聚半乳糖醛酸酶(PG)活性、共价性果胶(SSP)和水溶性果胶(WSP)含量呈现先增后降的趋势,果胶甲基酯酶(PME)活性呈下降趋势,离子型果胶(CSP)含量呈先降后增趋势。通过相关性分析发现,JA正向调控豆荚发育和纤维素代谢,ET、GA₃、6-BA、ABA则相反;JA通过抑制O2-向H2O2转化和POD活性来调控木质素的聚合,ET、GA₃、6-BA、ABA通过增强PAL和POD活性来促进木质素合成;IAA和SA参与调控果胶代谢。

The Relationship Between Changes of Endogenous Hormones and Cell Wall Metabolism of Common Bean During Bean Development

The cell wall metabolism of fresh common bean(Phaseolus vulgaris L.)seriously affects the edible quality.The contents of endogenous hormones,the main components and enzymes related to cell wall metabolism were analyzed in four developmental stages in beans’Dabaibang’,and the relationship between endogenous hormones and cell wall metabolism was analyzed.The results showed that the content of GA₃ and 6-BA decreased,the content of ethylene(ET)and JA decreased firstly and then increased during the development of pods.The pods was mainly in elongation growth before the 10 th day after anthesis,and the pods was mainly in thickening growth after the 10 th day after anthesis.Sucrose synthetase(SuSy)promoted sucrose synthesis before 10 days after anthesis.Sucrose content decreased and cellulose content increased with the decrease of SuSy and cellulase(Cx)activity.G-lignin deposition in xylem at 5 days after anthesis,G-lignin and S-lignin were deposited in phloem,gradually deepened and diffused to both sides after the 10 th day after anthersis.S-lignin was only deposited in phloem.The high phenylalanine ammonia lyase(PAL)activity provided the substrate for lignin biosynthesis at the 5 th day after anthesis,and then the increase of cinnamyl alcohol dehydrogenase(CAD)activity promoted lignin synthesis,the increase of superoxide dismutase(SOD)activity promoted the conversion of O2^-to H₂O₂,and the polymerization of lignin with peroxidase(POD)activity.Polygalacturonase(PG)activity,sodium-carbonate-soluble-pectin(SSP)and water-soluble-pectin(WSP)content increased firstly and then decreased,pectin methylesterase(PME)activity decreased,chelator-soluble-pectin(CSP)content decreased firstly and then increased.The correlation analysis showed that JA positively regulated pod development and cellulose metabolism,while ET,GA₃,6-BA and ABA were the opposite.JA regulates lignin polymerization by inhibiting the conversion of O2-to H2O2 and POD activity.ET,GA₃,6-BA and ABA promoted lignin synthesis by enhancing PAL and POD activity.IAA and SA were involved in regulation of pectin metabolism.