Murphy Kimberly A, Kuhle Rachel A, Fischer Andreas M, Anterola Aldwin M, Grimes Howard D
School of Molecular Biosciences, Washington State University, Pullman, WA 99164-6340, USA.
Graduate Program in Molecular Plant Sciences, Washington State University, Pullman, WA 99164-6340, USA.
Funct Plant Biol. 2005 May;32(4):335-344. doi: 10.1071/FP05006.
Antibodies raised against tonoplast intrinsic proteins (TIPs) were used to probe the functional status of the soybean [Glycine max (L.) Merr.] paraveinal mesophyll (PVM) vacuole during changes in nitrogen metabolism within the leaf. Young plants grown under standard conditions had PVM vacuoles characterised by the presence of γ-TIP, which is indicative of a lytic function. When plants were then subjected to shoot tip removal for a period of 15 d, forcing a sink-limited physiological condition, the γ-TIP marker diminished while the δ-TIP marker became present in the PVM vacuole, indicating the conversion of the PVM vacuole to a storage function. When the shoot tips were allowed to regrow, the γ-TIP marker again became dominant demonstrating the reversion of these PVM vacuoles back to a lytic compartment. The changes in TIP markers correlated with the accumulation of vegetative storage proteins and vegetative lipoxygenases, proteins implicated in nitrogen storage and assimilate partitioning. This research suggests that the PVM vacuole is able to undergo dynamic conversion between lytic and storage functions and further implicates this cell layer in assimilate storage and mobilisation in soybeans.
针对液泡膜内在蛋白（TIPs）产生的抗体被用于探究大豆[Glycine max (L.) Merr.]脉间叶肉（PVM）液泡在叶片氮代谢变化过程中的功能状态。在标准条件下生长的幼苗，其PVM液泡以存在γ-TIP为特征，这表明具有裂解功能。当对植株进行15天的去顶处理，迫使形成库限制的生理状态时，γ-TIP标记减少，而δ-TIP标记出现在PVM液泡中，这表明PVM液泡转变为储存功能。当茎尖重新生长时，γ-TIP标记再次占主导，表明这些PVM液泡又恢复为裂解区室。TIP标记的变化与营养储存蛋白和营养脂氧合酶的积累相关，这些蛋白与氮储存和同化物分配有关。该研究表明，PVM液泡能够在裂解和储存功能之间进行动态转换，并且进一步表明该细胞层参与大豆同化物的储存和调动。
