培养基组分对青杄离体花粉萌发和花粉管生长的影响

该文研究了青杄花粉在离体培养条件下,蔗糖、硼(H3BO3)和钙(CaCl2)对其萌发和花粉管生长的影响,同时还优化了培养基的组分配比.培养基中蔗糖浓度对青杄花粉的萌发影响显著,并有明显的域值效应;应用识别酯化果胶的单克隆抗体JIM7和酸性果胶的JIM5,分别对青杄花粉管进行免疫荧光标记,发现无硼培养可导致酸性果胶在其顶端细胞壁大量富集,而酯化果胶减少;荧光探针Fluo--3/AM标记实验揭示,无硼培养使其顶端胞质的Ca2 浓度梯度消失.研究结果表明,硼可能作为一种相关因子影响关键酶活性,改变细胞壁的延展性以至影响花粉管细胞壁的构建,同时破坏了花粉管顶端极性生长依赖的Ca2 梯度,从而影响其花粉管的生长.

Effects of medium components on in vitro pollen germination and pollen tube growth of Picea wilsonii Mast

The effects of sucrose,calcium(CaCl_2) and boron(H_3BO_3) on pollen germination and pollen tube growth of Picea wilsonii Mast.were investigated and then the optimal medium was determined.The results showed that pollen germination was strict to the concentration of sucrose in cultured medium and had a significant range effect.Immunochemical localization of acid pectin and methyl-esterified pectin in the walls of pollen tubes was investigated by using monoclonal antibody JIM5 and JIM7,and observed by means of confocal laser scanning microscopy(CLSM).Immunolabeling revealed that acidic pectin accumulated in the extreme tip region and esterified pectin was only located at basal sites in pollen tubes cultured in boron-deficient medium.Studying using Fluo-3/AM revealed that the boron-deficient treatment altered the cytoplasmic Ca~(2+) distribution pattern and Ca~(2+) gradient disappeared.The results imply that boron may function as a regulatory factor of pollen tube growth by affecting the activity of the corresponding enzymes,inducing the extensibility and thus the foundation of the cell wall,and destroying polarity growth-dependent Ca~(2+) gradient,which might also contribute to the regulation of pollen tube growth.