宁夏枸杞果实内源激素的变化及其与细胞壁成分和相关酶的关系

采用高效液相色谱技术, 研究了不同发育时期宁杞1号和宁杞5号枸杞(Lycium barbarum)果皮和种子内源激素(玉米素(ZT)、赤霉素(GA₃)、生长素(IAA)和脱落酶(ABA))含量与果实生长发育的关系。结果表明, 宁杞5号果实横纵径和单粒重均大于宁杞1号, 果实发育前期, 尤其是缓慢生长期, 是宁杞5号果实大小和重量积累的关键时期。宁杞1号种子中的生长素含量与果实横径和果实单粒重均呈极显著正相关, 与果实纵径呈显著正相关。宁杞5号果皮中玉米素含量与果实横径和单粒重均呈显著正相关, 种子中生长素含量与果实横径和单粒重均呈显著正相关。玉米素促进细胞的分裂, 而细胞数目比细胞体积对决定果实大小的作用更大; 在缓慢生长期(开花后8–25天), 宁杞5号果皮和种子中的脱落酸含量均显著小于宁杞1号。以上两点可能是宁杞5号的横纵径和单粒重均大于宁杞1号的主要原因。宁杞1号果皮中的GA₃与半纤维素酶(Cx)活性的变化相反, 说明宁杞1号果实发育前期和中期果皮中高含量的GA₃对细胞壁中Cx活性有一定的抑制作用, 从而表现出果实膨大。宁杞5号果皮中的IAA与多聚半乳糖醛酸酶(PG)和果胶酯酶(PE), ZT与PE, ABA与Cx, 种子中的ZT与PE的变化均相反, 说明宁杞5号果实发育前期和中期果皮中高含量的IAA、ZT、ABA及种子中的ZT可促进果实的膨大。推测这可能是宁杞5号果实单粒重大于宁杞1号的主要原因之一。宁杞5号果皮中的ZT和种子中的IAA可以增强Cx的活性; 宁杞1号果皮中的ABA可以增强PE的活性, 进而促进果实的成熟。

Changes in Endogenous Hormone Contents and Cell Wall Component,Degrading Enzyme Activity and Their Relation in Lycium barbarum

Using high-performance liquid chromatography, we examined the relationship between the content of endogenous hormones (zeatin ZT], gibberellic acid GA₃], indole acetic acid IAA], abscisic acid ABA]) during fruit growth and development in Lycium barbarum Ningqi 1 and Ningqi 5. The diameter, length, and single-fruit weight were greater in Ningqi 5 than Ningqi 1; the early stage of fruit development, especially in the slow growth period, was a critical period for Ningqi 5 and could increase fruit size and weight. In Ningqi 1, IAA content in seeds was positively correlated with diameter and single-fruit weight and length. In Ningqi 5, ZT content in pericarp and IAA content in seeds was positively correlated with diameter and single-fruit weight. ZT can promote cell division, and in fruit growth, the cell number is more important than the cell size. In the slow-growth period (8–25 d), the content of ABA in the pericarp and seed was lower in Ningqi 5 than Ningqi 1, which explains the greater diameter, length and single-fruit weight of Ningqi 5 than Ningqi 1. The changes in GA₃ and cellulase (Cx) were opposite, which indicated that Cx activity was inhibited by the high content of the pericarp GA₃ in prophase and metaphase in Ningqi 1, thus showing fruit swelling. The changes of IAA in pericarp and polygalacturonase (PG), pectinesterase (PE), ZT and PE, ABA and Cx, ZT in seeds and PE were opposite. As well, in prophase and metaphase of Ningqi 5, the high content of IAA, ZT and ABA in the pericarp and ZT in seeds could promote fruit expansion, which explains the larger fruit size in Ningqi 5 than Ningqi 1. In Ningqi 5, ZT content in the pericarp and IAA content in seeds could enhance the activity of Cx. In Ningqi 1, ABA content in the pericarp could enhance the activity of PE, then promote the maturation of fruit.