玛斯绿酶、草酸和 EGTA 对桃木质部薄壁组织的深过冷却和pit 膜结构的影响。

U.S. Department of Agriculture, Agricultural Research Service, North Atlantic Area, Appalachian Fruit Research Station, Kearneysville, West Virginia 25430.

Plant Physiol. 1991 Aug;96(4):1354-9. doi: 10.1104/pp.96.4.1354.

The object of this study was to determine if calcium cross-linking of pectin in the pit membrane of xylem parenchyma restricts water movement which results in deep supercooling. Current year shoots of ;Loring' peach (Prunus persica) were infiltrated with oxalic acid or EGTA solutions for 24 or 48 hours and then either prepared for ultrastructural analysis or subjected to differential thermal analysis. The effect of 0.25 to 1.0% pectinase (weight/volume) on deep supercooling was also investigated. The use of 5 to 50 millimolar oxalic acid and pectinase resulted in a significant reduction (flattening) of the low temperature exotherm and a distinct swelling and partial degradation of the pit membrane. EGTA (10 millimolar) for 24 or 48 hours shifted the low temperature exotherm to warmer temperatures and effected the outermost layer of the pit membrane. A hypothesis is presented on pectin-mediated regulation of deep supercooling of xylem parenchyma.

本研究的目的是确定木质部薄壁组织的pit 膜中果胶的钙交联是否会限制水分运动，从而导致深过冷。用草酸或 EGTA 溶液处理‘Loring’桃（Prunus persica）当年生新梢 24 或 48 小时，然后进行超微结构分析或差示热分析。还研究了 0.25%至 1.0%果胶酶（重量/体积）对深过冷的影响。使用 5 至 50 毫摩尔草酸和果胶酶会导致低温放热显著减少（变平），pit 膜明显肿胀和部分降解。24 或 48 小时的 EGTA（10 毫摩尔）将低温放热转移到较暖的温度，并影响 pit 膜的最外层。提出了一个关于果胶介导的木质部薄壁组织深过冷调节的假说。