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Expansin的研究进展 总被引:8,自引:0,他引:8
随着对植物生长机制的不断深入研究,发现expansin蛋白具明显而广泛的促进生长的作用。简述了expansin蛋白的生化特性及其对细胞壁的松弛机制,同时介绍了expansin在水稻中的组织定位。 相似文献
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Silvia Dal Santo Marianna Fasoli Erika Cavallini Giovanni Battista Tornielli Mario Pezzotti Sara Zenoni 《Plant signaling & behavior》2011,6(12):2031-2034
Expansins are wall-loosening proteins that induce wall stress relaxation and irreversible wall extension in a pH-dependent manner. Despite a substantial body of work has been performed on the characterization of many expansins genes in different plant species, the knowledge about their precise biological roles during plant development remains scarce. To yield insights into the expansion process in Petunia hybrida, PhEXPA1, an expansin gene preferentially expressed in petal limb, has been characterized. The constitutive overexpression of PhEXPA1 significantly increased expansin activity, cells size and organ dimensions. Moreover, 35S::PhEXPA1 transgenic plants exhibited an altered cell wall polymer composition and a precocious timing of axillary meristem development compared with wild-type plants. These findings supported a previous hypothesis that expansins are not merely structural proteins involved in plant cell wall metabolism but they also take part in many plant development processes. Here, to support this expansins dual role, we discuss about differential cell wall-related genes expressed in PhEXPA1 expression mutants and gradients of altered petunia branching pattern. 相似文献
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《Fungal Biology Reviews》2020,34(1):13-24
Twenty years of research on cerato-platanin family proteins (CPPs) have led to some clear conclusions: CPPs are exclusively present in the fungal kingdom and possess an outstanding capacity to stimulate the immune system of plants. Recent discoveries have highlighted remarkable structural and functional similarities between CPPs and expansins, a class of non-enzymatic proteins found in both plants and microbes possessing loosening ability on the cell wall structure. Nevertheless, the determination of a biological role for CPPs in fungi is becoming a complicated puzzle to solve, since experimental data are often divergent and point to functional diversification. A general consensus appears however possible: CPPs from pathogenic and beneficial fungi may be considered as microbe-associated molecular patterns (MAMPs) and likely play a dual role, exerting functions in the fungal cell wall and/or in plant colonization. In this review, which celebrates 20 y of research on CPPs, we trace the history of these proteins and highlight experimental evidence and still unsolved issues. 相似文献
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We investigated the involvement of expansin action in determining the growth rate of internodes of floating rice (Oryza sativa L.). Floating rice stem segments in which rapid internodal elongation had been induced by submergence for 2 days were exposed
to air or kept in submergence for 2 more days. Both treatments reduced the elongation rate of the internodes, and the degree
of reduction was much greater in air-exposed stem segments than in continually submerged segments. These rates of internodal
elongation were correlated with acid-induced cell wall extensibility and cell wall susceptibility to expansins in the cell
elongation zone of the internodes, but not with extractable expansin activity. These results suggest that the reduced growth
rate of internodes must be due, at least in part, to the decrease in acid-induced cell wall extensibility, which can be modulated
through changes in the cell wall susceptibility to expansins rather than through expansin activity. Analysis of the cell wall
composition of the internodes showed that the cellulosic and noncellulosic polysaccharide contents increased in response to
exposure to air, but they remained almost constant under continued submergence although the cell wall susceptibility to expansins
gradually declined even under continued submergence. The content of xylose in noncellulosic neutral sugars in the cell walls
of internodes was closely and negatively correlated with changes in the susceptibility of the walls to expansins. These results
suggest that the deposition of xylose-rich polysaccharides into the cell walls may be related to a decrease in acid-induced
cell wall extensibility in floating rice internodes through the modulation of cell wall susceptibility to expansins. 相似文献
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Biochemical dissection of the “acid-growth” process of plant cell walls led to the isolation of a new class of wall loosening
proteins, called expansins. These proteins affect the rheology of growing walls by permitting the microfibril-matrix network
to slide, thereby enabling the wall to expand. Molecular sequence analysis suggests that expansins might have a cryptic glycosyl
transferase activity, but biochemical results suggest that expansins disrupt noncovalent bonding between microfibrils and
the matrix. Recent discoveries of a new expansin family and gene expression in fruit, meristerms and cotton fibers have enlarged
our view of the developmental functions of this group of wall loosening proteins. 相似文献