Responses of pollen tube cells and cultured roots of tea to aluminum stress

近年来，细胞内Ca^++水平对植物多种生理活动的影响已引起人们的广泛关注。在这项研究中，我们的目的是直接测量铝胁迫或刺激对细胞质Ca^++>活性在茶树花粉管生长的荧光探针，Indo-1。(1)荧光分光光度法测定茶树花粉管细胞胞质Ca^++方法的建立用Ca探针Indo-1以nM水平测定了花粉管细胞中Ca^<++>的细胞内水平。在含有Indo-1AM的茶树花粉管生长培养基中加入铝2-4小时后，细胞质Ca^++活性升高到400 nM以上。(2)铝、硼对茶树花粉管细胞质Ca^++升高的影响在低硼（0.01mM）培养基中，加入5 μ M的铝可使细胞内Ca ~（++）升高，而在高硼培养基中，加入3 μ M的铝可使细胞内Ca ~（++）升高。另一方面，随着硼浓度的增加，细胞内Ca^++>含量增加，而在3 μ M铝浓度下，细胞内Ca ^++含量没有增加，这表明铝在一定程度上替代了硼在茶树花粉管中的功能作用。也表明铝是一种激发子。

Recently, the effect of intracellular level of Ca^<++> on a variety of physiological activities in plants has been markedly attented. In this study, our objective was to directly measure the effect of aluminum stress or stimulation on cytoplasmic Ca^<++> activity in tea pollen tube growth using the fluorescent Ca probe, Indo-1.(1) Establishment of method for determination of cytoplasmic Ca^<++> in tea pollen tube cells by the fluorescence spectrophometer. Intracellular levels of Ca^<++> in pollen tube cells were measured at nM level with Ca probe Indo-1. When aluminum was supplied to tea pollen tube growth medium with Indo-1AM for 2-4 hrs, the cytoplasmic Ca^<++> activity elevated above 400 nM.(2) Effect of aluminum or boron on the elevation of cytoplasmic Ca^<++> in tea pollen tube cells. It was observed that intracellular Ca^<++> elevated by 5muM aluminum supply in the medium of low boron (0.01 mM), and by 3muM in the medium of sufficient boron. On the other hand, it was observed that intracellular Ca^<++> was elevated with increasing application of boron into medium, but not observed in the presence of 3muM aluminum.These results suggest that aluminum substitutes the part of the functional role of boron in tea pollen tubes. and also show that aluminum acts as a elicitor.