由于极地独特的地理、气候及环境特点,使得极地微生物及其代谢产物具有新颖性与多样性。采用3种选择性培养基的稀释平板涂布法,从南极普里兹湾海洋沉积物中分离得到4株真菌菌株,经过形态学、18s r DNA-ITS序列分析,分别鉴定为隐球酵母Cr...由于极地独特的地理、气候及环境特点,使得极地微生物及其代谢产物具有新颖性与多样性。采用3种选择性培养基的稀释平板涂布法,从南极普里兹湾海洋沉积物中分离得到4株真菌菌株,经过形态学、18s r DNA-ITS序列分析,分别鉴定为隐球酵母Cryptococcus sp.NJF1、曲霉Aspergillus sp.NJF3、枝孢霉Cladosporium sp.NJF4和Cladosporium sp.NJF6;对其中的曲霉NJF3、枝孢霉NJF4和NJF6等3株真菌开展了蛋白磷酸酶含量和大田软海绵酸OA对该酶的抑制作用测试,并分析了菌株提取物中的脂肪酸成分。结果显示:NJF3、NJF4和NJF6有很好的蛋白磷酸酶活性,以蛋白磷酸酶-PP为外标,测定酶含量分别为0.732 2 U·g-1、0.678 U·g-1和1.229 2 U·g-1,且100 n M OA对NJF3和NJF4蛋白磷酸酶有一定抑制作用,而NJF6需要200 n M OA才可以轻微抑制其蛋白磷酸酶活性;3株真菌的脂肪酸成分以油酸为主,相对含量分别达到32.4%、37.2%、40.1%,而NJF4和NJF6还含有较高含量的亚油酸,相对含量分别达到27.3%、29.8%。本研究可为下一步开展菌株的酶、天然代谢产物研究奠定基础。展开更多
Polar auxin transport,which depends on polarized subcellular distribution of AUXIN RESISTANT 1/LIKE AUX1（AUX1/LAX） influx carriers and PIN-FORMED（PIN） efflux carriers,mediates various processes of plant growth and...Polar auxin transport,which depends on polarized subcellular distribution of AUXIN RESISTANT 1/LIKE AUX1（AUX1/LAX） influx carriers and PIN-FORMED（PIN） efflux carriers,mediates various processes of plant growth and development.Endosomal recycling of PIN1 is mediated by an adenosine diphosphate（ADP）ribosylation factor（ARF）-GTPase exchange factor protein,GNOM.However,the mediation of auxin influx carrier recycling is poorly understood.Here,we report that overexpression of OsAGAP,an ARF-GTPase-activating protein in rice,stimulates vesicle transport from the plasma membrane to the Golgi apparatus in protoplasts and transgenic plants and induces the accumulation of early endosomes and AUX1.AUX1 endosomes could partially colocalize with FM4-64 labeled early endosome after actin disruption.Furthermore,OsAGAP is involved in actin cytoskeletal organization,and its overexpression tends to reduce the thickness and bundling of actin filaments.Fluorescence recovery after photobleaching analysis revealed exocytosis of the AUX1 recycling endosome was not affected in the OsAGAP overexpression cells,and was only slightly promoted when the actin filaments were completely disrupted by Lat B.Thus,we propose that AUX1 accumulation in the OsAGAP overexpression and actin disrupted cells may be due to the fact that endocytosis of the auxin influx carrier AUX1 early endosome was greatly promoted by actin cytoskeleton disruption.展开更多
The techniques of oxygen electrode polarogra-phy and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and ...The techniques of oxygen electrode polarogra-phy and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and structural aspects of photosystem Ⅱ (PS Ⅱ) through enzymatic approach. It was shown that the depletion of PG by treatment of phospholipase C (PLC) on PS Ⅱ particles caused the inhibition of oxygen evolving activity in PS Ⅱ. This effect also gave rise to changes in the protein secondary structures of PS Ⅱ, that is, an increase in a-helical conformation which is compensated by the loss of p-strand structures. It revealed that the head-group of PG molecules plays an important structural role in the maintenance of normal structure of PS Ⅱ proteins, which is required to maintain the appropriate physiological activity of the PS Ⅱ complex such as the oxygen evolving activity. It is suggested that there most probably exist hydrogen-bonding interactions between PG molecules and PS Ⅱ proteins.展开更多
文摘由于极地独特的地理、气候及环境特点,使得极地微生物及其代谢产物具有新颖性与多样性。采用3种选择性培养基的稀释平板涂布法,从南极普里兹湾海洋沉积物中分离得到4株真菌菌株,经过形态学、18s r DNA-ITS序列分析,分别鉴定为隐球酵母Cryptococcus sp.NJF1、曲霉Aspergillus sp.NJF3、枝孢霉Cladosporium sp.NJF4和Cladosporium sp.NJF6;对其中的曲霉NJF3、枝孢霉NJF4和NJF6等3株真菌开展了蛋白磷酸酶含量和大田软海绵酸OA对该酶的抑制作用测试,并分析了菌株提取物中的脂肪酸成分。结果显示:NJF3、NJF4和NJF6有很好的蛋白磷酸酶活性,以蛋白磷酸酶-PP为外标,测定酶含量分别为0.732 2 U·g-1、0.678 U·g-1和1.229 2 U·g-1,且100 n M OA对NJF3和NJF4蛋白磷酸酶有一定抑制作用,而NJF6需要200 n M OA才可以轻微抑制其蛋白磷酸酶活性;3株真菌的脂肪酸成分以油酸为主,相对含量分别达到32.4%、37.2%、40.1%,而NJF4和NJF6还含有较高含量的亚油酸,相对含量分别达到27.3%、29.8%。本研究可为下一步开展菌株的酶、天然代谢产物研究奠定基础。
基金supported by the Innovative Program of the Chinese Academy of Sciences (KSCX2-YW-N-041)the National Natural Science Foundation of China(30670197)
文摘Polar auxin transport,which depends on polarized subcellular distribution of AUXIN RESISTANT 1/LIKE AUX1（AUX1/LAX） influx carriers and PIN-FORMED（PIN） efflux carriers,mediates various processes of plant growth and development.Endosomal recycling of PIN1 is mediated by an adenosine diphosphate（ADP）ribosylation factor（ARF）-GTPase exchange factor protein,GNOM.However,the mediation of auxin influx carrier recycling is poorly understood.Here,we report that overexpression of OsAGAP,an ARF-GTPase-activating protein in rice,stimulates vesicle transport from the plasma membrane to the Golgi apparatus in protoplasts and transgenic plants and induces the accumulation of early endosomes and AUX1.AUX1 endosomes could partially colocalize with FM4-64 labeled early endosome after actin disruption.Furthermore,OsAGAP is involved in actin cytoskeletal organization,and its overexpression tends to reduce the thickness and bundling of actin filaments.Fluorescence recovery after photobleaching analysis revealed exocytosis of the AUX1 recycling endosome was not affected in the OsAGAP overexpression cells,and was only slightly promoted when the actin filaments were completely disrupted by Lat B.Thus,we propose that AUX1 accumulation in the OsAGAP overexpression and actin disrupted cells may be due to the fact that endocytosis of the auxin influx carrier AUX1 early endosome was greatly promoted by actin cytoskeleton disruption.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39890390) the State Basic Research Development Plan of China (Grant No. G1998010100)the Innovative Foundation of Laboratory of Photosynthesis Basic Research, Insti
文摘The techniques of oxygen electrode polarogra-phy and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and structural aspects of photosystem Ⅱ (PS Ⅱ) through enzymatic approach. It was shown that the depletion of PG by treatment of phospholipase C (PLC) on PS Ⅱ particles caused the inhibition of oxygen evolving activity in PS Ⅱ. This effect also gave rise to changes in the protein secondary structures of PS Ⅱ, that is, an increase in a-helical conformation which is compensated by the loss of p-strand structures. It revealed that the head-group of PG molecules plays an important structural role in the maintenance of normal structure of PS Ⅱ proteins, which is required to maintain the appropriate physiological activity of the PS Ⅱ complex such as the oxygen evolving activity. It is suggested that there most probably exist hydrogen-bonding interactions between PG molecules and PS Ⅱ proteins.
