机构地区: 肇庆学院生命科学学院
出 处: 《植物生理学报》 2011年第11期1096-1102,共7页
摘 要: 盐胁迫(75mmol·L-1NaCl)下,枣树微茎段外植体成活率、生根率及枣苗的侧根条数和长度、苗高、单株重量均较对照显著减小;盐胁迫下加硅(Si)(0.75mmol·L-1KSiO3),枣苗的前述指标与对照无显著性差异。盐胁迫下,枣组织培养生根苗细胞壁提取率显著下降,细胞壁中蛋白和低分子量果胶含量显著降低,EDTA可溶性果胶和碱溶性果胶含量显著提高,半纤维素和纤维素含量降低;盐胁迫下加Si,枣苗细胞壁提取率显著提高,细胞壁主要成分的含量水平与对照相近。与盐胁迫下相比,盐胁迫下加Si,虽然枣苗果胶甲酯酶(PME)和多聚半乳糖醛酸酶(PG)活性升高未达显著性差异水平,但纤维素酶(Cx)活性显著降低,3种水解酶活性的比值均显著增大,细胞壁共价结合态H+-ATP酶活性显著升高。结果说明,提高培养基可溶性Si水平,可显著改善受盐胁迫枣苗细胞壁水解酶的活性平衡、组分含量的均衡及细胞壁内外溶质的适应性分配,从而为枣苗较好生长奠定了基础。 Substem explant survival rate and rooting rate and lateral root number, length of each lateral root, height and flesh weight of single rooting plantlet of Chinese jujube (Ziziphus jujuba) significantly decreased under salt stress (75mmol·L^-1 NaCl), but all of these indexes antecedent were of no significance under salt stress with added Si (0.75mmol·L^-1 KSiO3) compared with control. Under salt stress, cell wall extraction rate of the rooted plantlets significantly decreased, protein and low-molecular pectin contents in cell wall significantly decreased, hemicellulose and cellulose contents decreased, both content of pectin separated with chelating agent (EDTA) and content of alkali-soluble pectin significantly increased, but cell wall extraction rate of the plantlets significantly increased and main components in cell wall of the plantlets under salt stress with added Si were similar to control. Under salt stress with added Si, though pectin methylesterase (PME) and polygalacturonase (PG) activities of the rooted plantlets did not significantly increase, cellulase (Cx) activity decreased significantly, in particular activity ratios of the three enzymes increased significantly, and covalently cell wall-bound H^+-ATPase activity significantly increased compared with those of under salt stress. The experimental results strongly indicates that increasing soluble Si content in medium significantly improves activity balance of cell wall hydrolases, relative proportionality of cell wall constitutions and adaptive distribution to soluble substrates in/out cell wall of rooted plantlets of Chinese jujube under salt stress, which provide efficient help for better growth of the plantlets under salt stress.