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

近年来，细胞内Ca~(2+)水平对植物多种生理活动的影响已引起人们的广泛关注。本研究的目的是利用荧光钙探针INDO-1直接测定铝胁迫或刺激对茶树花粉管生长过程中细胞质Ca~(2+)活性的影响。(1)建立了用荧光分光光度计法测定茶叶花粉管细胞胞质Ca~(2+)的方法。用INDO-1钙探针在纳米水平上测定花粉管细胞内钙离子水平。在含Indo-1AM的茶树花粉管细胞培养液中加铝2-4小时后，胞质Ca~(2+)&lt；++&gt；活性升高。(2)铝或硼对茶树花粉管细胞胞质Ca~(2+)&lt；++&gt_1升高的影响。结果表明，在低硼(0.01 mM)和高硼(0.01 mM)条件下，细胞内钙离子浓度分别增加5µM和3µM。另一方面，细胞内Ca~(2+)~+-Gt~(2+)随培养液中硼施用量的增加而升高，但在3um~M铝的存在下，细胞内Ca~(2+)~(++)~(gt；)升高，提示铝替代了硼在茶树花粉管中的部分功能作用。同时也表明铝起到了引发剂的作用。

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.