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Sugars act as vital signaling molecules that regulate plant growth, development and stress responses. However, the effects of sugars on stomatal movement have been unclear. In our study, we explored the effects of monosaccharides such as glucose and mannose on stomatal aperture. Here, we demonstrate that glucose and mannose trigger stomatal closure in a dose‐ and time‐dependent manner in epidermal peels of broad bean (Vicia faba). Pharmacological studies revealed that glucose‐ and mannose‐induced stomatal closure was almost completely inhibited by two reactive oxygen species (ROS) scavengers, catalase (CAT) and reduced glutathione (GSH), was significantly abolished by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI), whereas they were hardly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM). Furthermore, glucose‐ and mannose‐induced stomatal closure was strongly inhibited by a Ca2+ channel blocker, LaCl3, a Ca2+ chelator, ethyleneglycol‐bis(beta‐aminoethylether)‐N,N'‐tetraacetic acid (EGTA) and two water channel blockers, HgCl2 and dimethyl sulfoxide (DMSO); whereas the inhibitory effects of the water channel blockers were essentially abolished by the reversing agent β‐mercaptoethanol (β‐ME). These results suggest that ROS production mainly via NADPH oxidases, Ca2+ and water channels are involved in glucose‐ and mannose‐induced stomatal closure. 相似文献
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Zhaozhou?Li Xiujin?ChenEmail author Zhili?Li Daomin?Li Yao?Wang Hongli?Gao Li?Cao Yuze?Hou Songbiao?Li Jianping?Liang 《Biotechnology letters》2016,38(6):983-989
Objectives
To improve cellulase production and activity, Trichoderma viride GSICC 62010 was subjected to mutation involving irradiation with an electron beam and subsequently with a 12C6+-ion beam.Results
Mutant CIT 626 was the most promising cellulase producer after preliminary and secondary screening. Soluble protein production and cellulase activities were increased mutifold. The optimum temperature, pH and culture time for the maximum cellulase production of the selected mutant were 35 °C, pH 5 and 6 days. The highest cellulase production was obtained using wheat bran. The prepared cellulases from T. viride CIT 626 had twice the hydrolytic performance with sawdust (83 %) than that from the parent strain (42.5 %). Furthermore, molecular studies demonstrated that there were some key mutation sites suggesting that some amino acid changes in the protein caused by base mutations had led to the enhanced cellulase production and activity.Conclusions
Mutagenesis with electron and 12C6+-ion beams could be developed as an effective tool for improvement of cellulase producing strains.918.
Objective
To investigate the cellulose modification process on kraft pulp during recycling by mono-endoglucanase.Results
Pichia pastoris expressing endoglucanase, EG1, was grown in a 10 l fermenter yielding a high carboxymethyl cellulase (CMCase) activity of 340 U mg?1. EG1-mediated modification of kraft pulp resulted in a paper sheet with the tensile index and burst index increased by 10 and 6.5 %, respectively. The kink index (indicating abrupt bends in fibres) of the enzyme-treated group decreased sharply by 45 % after the first recycling, compared with a reduction of only 1 % in the control group. Furthermore, EG1 treatment decreased the growth of crystallinity from 73.5 to 73.2 % and crystal size from 7.45 to 7.21 nm, which alleviated paper aging.Conclusion
Endoglucanase EG1 modifies the interfacial properties of fibers, which affects fibre morphology during the recycling process and improves the technical properties of the resulting pulp and paper.919.
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