Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China; Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Peoples R China
WOS标题词:
Science & Technology
; Life Sciences & Biomedicine
类目[WOS]:
Biochemistry & Molecular Biology
; Plant Sciences
研究领域[WOS]:
Biochemistry & Molecular Biology
; Plant Sciences
摘要:
Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The present study examined the effects of different light conditions and sugars on the differentiation of Nostoc sphaeroides Kutzing to the hormogonia stage. Results showed that differentiation of hormogonia was light dependent in the absence of sugar, but that close to 100% of cyanobacteria differentiated to hormogonia in the presence of glucose or sucrose, irrespective of the light conditions. This differentiation was inhibited, even in the presence of sugars, upon application of an inhibitor of respiration. Following the testing of different sugars, the effects of different lights were examined. It was found that 5 10 μ mol.m(-2)• s(-1) photon flux density was optimal for hormogonia differentiation. One hundred percent differentiation was obtained with white light irradiation, in contrast with irradiation with green light (80% differentiation) and red light (0-10% differentiation). Although they showed different efficiencies in inducing hormogonia differentiation in N. sphaeroides, the green and red radiation did not display antagonistic effects. When the additional aspect of time dependence was investigated through the application of different light radiations and an inhibitor of protein synthesis, it was found that the initial 6 h of the differentiation process was crucial for hormogonia differentiation. Taken together, these results show that hormogonia differentiation in N. sphaeroides is either a photoregulated or an energy dependent process.
英文摘要:
Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The present study examined the effects of different light conditions and sugars on the differentiation of Nostoc sphaeroides Kutzing to the hormogonia stage. Results showed that differentiation of hormogonia was light dependent in the absence of sugar, but that close to 100% of cyanobacteria differentiated to hormogonia in the presence of glucose or sucrose, irrespective of the light conditions. This differentiation was inhibited, even in the presence of sugars, upon application of an inhibitor of respiration. Following the testing of different sugars, the effects of different lights were examined. It was found that 5 10 μ mol.m(-2)• s(-1) photon flux density was optimal for hormogonia differentiation. One hundred percent differentiation was obtained with white light irradiation, in contrast with irradiation with green light (80% differentiation) and red light (0-10% differentiation). Although they showed different efficiencies in inducing hormogonia differentiation in N. sphaeroides, the green and red radiation did not display antagonistic effects. When the additional aspect of time dependence was investigated through the application of different light radiations and an inhibitor of protein synthesis, it was found that the initial 6 h of the differentiation process was crucial for hormogonia differentiation. Taken together, these results show that hormogonia differentiation in N. sphaeroides is either a photoregulated or an energy dependent process.
1.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China 2.Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Peoples R China
Recommended Citation:
Dun-Hai LI;Lan-Zhou CHEN;Gen-Bao LI;Gao-Hong WANG;Li-Rong SONG and Yong-Ding LIU.Photoregulated or energy dependent process of hormogonia differentiation in Nostoc sphaeroides Kutzing (Cyanobacterium),JOURNAL OF INTEGRATIVE PLANT BIOLOGY,2005,47(6):709-716
