Genotypic and developmental evidence for the role of plasmodesmatal regulation in cotton fiber elongation mediated by callose turnover
Genotypic and developmental evidence for the role of plasmodesmatal regulation in cotton fiber elongation mediated by callose turnover
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DOI：
10.1104/pp.104.051540
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发表时间：
2004-12-01
期刊：
影响因子：
7.4
通讯作者：
Furbank, RT
中科院分区：
文献类型：
--
作者：
Ruan, YL;Xu, SM;Furbank, RT
棉纤维是单细胞毛，从四倍体种皮表皮延伸到几厘米长（棉棉和棉棉）。因此，棉纤维是研究细胞快速膨胀机理的独特体系。先前的研究表明，在纤维伸长（y - l）过程中，胞间连丝有短暂的闭合。王晓明，王晓明，王晓明，等[2001]植物科学进展(2):1 -6。为了研究这种关闭对纤维伸长的重要性，我们比较了不同基因型棉花纤维长度不同的间连丝关闭的持续时间。膜外荧光分子羧基荧光素的共聚焦成像显示，三种四倍体基因型和两种二倍体祖细胞间连丝闭合时间的基因型差异与纤维长度呈正相关。在所有情况下，闭合发生在伸长的快速阶段。苯胺蓝染色和免疫定位研究表明，纤维基部的胼胝质沉积和降解分别与间连丝关闭和重新开放的时间相关。Northern分析表明，当胼胝质沉积在纤维基部时，纤维特异性β -1,3-葡聚糖酶基因GhGluc1的表达未被检测到，但在胼胝质降解时，该基因的表达变得明显。基因型上，GhGluc1在短纤维基因型中表达量高，在中、长纤维基因型中表达量弱。这些数据提供了基因型和发育证据：(1)胞间连丝的关闭似乎在棉纤维的延长中起重要作用；(2)胞间连丝的关闭和重新打开可能分别涉及胼胝质的沉积和降解；(3)GhGluc1的表达可能通过降解胼胝质的从而打开胞间连丝来参与这一过程。
Cotton fibers are single-celled hairs that elongate to several centimeters long from the seed coat epidermis of the tetraploid species (Gossypium hirsutum and Gossypium barbadense). Thus, cotton fiber is a unique system to study the mechanisms of rapid cell expansion. Previous work has shown a transient closure of plasmodesmata during fiber elongation (Y.-L. Ruan, D.J. Llewellyn, R.T. Furbank [2001] Plant Cell 13: 47-60). To examine the importance of this closure in fiber elongation, we compared the duration of the plasmodesmata closure among different cotton genotypes differing in fiber length. Confocal imaging of the membrane-impermeant fluorescent molecule carboxyfluorescein revealed a genotypic difference in the duration of the plasmodesmata closure that positively correlates with fiber length among three tetraploid genotypes and two diploid progenitors. In all cases, the closure occurred at the rapid phase of elongation. Aniline blue staining and immunolocalization studies showed that callose deposition and degradation at the fiber base correlates with the timing of plasmodesmata closure and reopening, respectively. Northern analyses showed that the expression of a fiber-specific beta-1,3-glucanase gene, GhGluc1, was undetectable when callose was deposited at the fiber base but became evident at the time of callose degradation. Genotypically, the level of GhGluc1 expression was high in the short fiber genotype and weak in the intermediate and long fiber genotypes. The data provide genotypic and developmental evidence that (1) plasmodesmata closure appears to play an important role in elongating cotton fibers, (2) callose deposition and degradation may be involved in the plasmodesmata closure and reopening, respectively, and (3) the expression of GhGluc1 could play a role in this process by degrading callose, thus opening the plasmodesmata.