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41.
Biological functions of proline in morphogenesis and osmotolerance revealed in antisense transgenic Arabidopsis thaliana 总被引:10,自引:0,他引:10
Tokihiko Nanjo Masatomo Kobayashi Yoshu Yoshiba Yukika Sanada Keishiro Wada Hirokazu Tsukaya Yoshitaka Kakubari Kazuko Yamaguchi-Shinozaki Kazuo Shinozaki 《The Plant journal : for cell and molecular biology》1999,18(2):185-193
Many organisms, including higher plants, accumulate free proline (Pro) in response to osmotic stress. Although various studies have focused on the ability of Pro as a compatible osmolyte involved in osmotolerance, its specific role throughout plant growth is still unclear. It has been reported that Pro is synthesized from Glu catalyzed by a key enzyme, delta 1-pyrroline-5-carboxylate synthetase (P5CS), in plants. To elucidate essential roles of Pro, we generated antisense transgenic Arabidopsis plants with a P5CS cDNA. Several transgenics accumulated Pro at a significantly lower level than wild-type plants, providing direct evidence for a key role of P5CS in Pro production in Arabidopsis. These antisense transgenics showed morphological alterations in leaves and a defect in elongation of inflorescences. Furthermore, transgenic leaves were hypersensitive to osmotic stress. Microscopic analysis of transgenic leaves, in which the mutated phenotype clearly occurred, showed morphological abnormalities of epidermal and parenchymatous cells and retardation of differentiation of vascular systems. These phenotypes were suppressed by exogenous L-Pro but not by D-Pro or other Pro analogues. In addition, Pro deficiency did not broadly affect all proteins but specifically affected structural proteins of cell walls in the antisense transgenic plants. These results indicate that Pro is not just an osmoregulator in stressed plants but has a unique function involved in osmotolerance as well as in morphogenesis as a major constituent of cell wall structural proteins in plants. 相似文献
42.
Comparative proteomics analysis of differentially expressed proteins in soybean cell wall during flooding stress 总被引:1,自引:0,他引:1
Setsuko Komatsu Yukito Kobayashi Keito Nishizawa Yohei Nanjo Kiyoshi Furukawa 《Amino acids》2010,39(5):1435-1449
Flooding is a major problem for soybean crop as it reduces the growth and grain yield. To investigate the function of the
soybean cell wall in the response to flooding stress, cell wall proteins were analyzed. Cell wall proteins from roots and
hypocotyls of soybeans, which were germinated for 2 days and subjected to 2 days of flooding, were purified, separated by
two-dimensional polyacrylamide gel electrophoresis and stained with Coomassie brilliant blue. Sixteen out of 204 cell wall
proteins showed responses to flooding stress. Of these, two lipoxygenases, four germin-like protein precursors, three stem
28/31 kDa glycoprotein precursors, and one superoxide dismutase [Cu–Zn] were downregulated. A copper amine oxidase was found
to have shifted from the basic to acidic zone following flooding stress. Based on these results, it was confirmed by the lignin
staining that the lignification was suppressed in the root of soybean under the flooding stress. These results suggest that
the roots and hypocotyls of soybean caused the suppression of lignification through decrease of these proteins by downregulation
of reactive oxygen species and jasmonate biosynthesis under flooding stress. 相似文献
43.
Chitosanase from the culture filtrate of Nocardia orientalis was purified to apparent homogeneity by precipitation with ammonium sulfate followed by CM-Sephadex chromatography, biospecific affinity chromatography on a Sepharose CL-4B with immobilized chitotriose and by gel filtration on Sephadex G-75. The enzyme specifically acted on chitooligosaccharides and chitosan to yield chitobiose and chitotriose as final products. The mode of action of the chitosanase on chitooligosaccharides and their corresponding alcohols suggests that the enzyme requires substrates with four or more glucosamine residues for the expression of activity and its shows maximum activity on chitohexaose and chitoheptaose. In the hydrolysis of chitosans of varying N-acetyl content, the enzyme cleaved about 30% acetylated chitosan with maximum activity and the enzyme activity decreased with increasing the degree of deacetylation of chitosans tested. The analysis of products formed from 33% acetylated chitosan shows the chitosanase is capable of cleaving between glucosamine and glucosamine or N-acetylglucosamine, but not cleaving between N-acetylglucosamine and glucosamine. On the basis of the results, the whole pathway of enymatic degradation of partially acetylated chitosan by a combination of chitosanase, exo-beta-D-glucosaminidase and beta-N-acetylhexosaminidase is proposed. 相似文献
44.
Monitoring expression profiles of Arabidopsis gene expression during rehydration process after dehydration using ca 7000 full-length cDNA microarray 总被引:14,自引:0,他引:14
45.
Hamid Sobhanian Roya Razavizadeh Yohei Nanjo Ali Akbar Ehsanpour Ferdous Rastgar Jazii Nasrin Motamed Setsuko Komatsu 《Proteome science》2010,8(1):19
Background
Salinity is one of the most widespread agricultural problems in arid and semi-arid regions that makes fields unproductive, and soil salinization is a serious problem in the entire world. To determine the effects of salt stress on soybean seedlings, a proteomic technique was used. 相似文献46.
Reducing sugars induced alkali-labile sites in DNA. The DNA reacted with D-fructose 6-phosphate or D-fructose in the presence of Cu2+ was cleaved by the treatment with aqueous piperidine at 90 degrees C for 30 min. Alkali-labile sites were induced frequently at the pyrimidine residues, especially at the pyrimidine residues in pyrimidine-purine (5'----3') sequences. Transition metal ions such as Cu2+ and oxygen radicals such as hydrogen peroxide were possibly involved in the induction of alkali-labile sites. 相似文献
47.
48.
Vincent Kwok Lim Lam Ronald Ching Wan Ma Heung Man Lee Cheng Hu Kyong Soo Park Hiroto Furuta Ying Wang Claudia Ha Ting Tam Xueling Sim Daniel Peng-Keat Ng Jianjun Liu Tien-Yin Wong E. Shyong Tai Andrew P. Morris DIAGRAM Consortium Nelson Leung Sang Tang Jean Woo Ping Chung Leung Alice Pik Shan Kong Risa Ozaki Wei Ping Jia Hong Kyu Lee Kishio Nanjo Gang Xu Maggie Chor Yin Ng Wing-Yee So Juliana Chung Ngor Chan 《PloS one》2013,8(6)
49.
Mass spectrometry-based analysis of proteomic changes in the root tips of flooded soybean seedlings 总被引:1,自引:0,他引:1
Nanjo Y Skultety L Uváčková L Klubicová K Hajduch M Komatsu S 《Journal of proteome research》2012,11(1):372-385
Flooding injury is a major problem in soybean cultivation. A proteomics approach was used to clarify the occurrence of changes in protein expression level and phosphorylation in soybeans under flooding stress. Two-day-old seedlings were flooded for 1 day, proteins were extracted from root tips of the seedlings and digested with trypsin, and their expression levels and phosphorylation states were compared to those of untreated controls using mass spectrometry-based proteomics techniques. Phosphoproteins were enriched using a phosphoprotein purification column prior to digestion and mass spectrometry. The expression of proteins involved in energy production increased as a result of flooding, while expression of proteins involved in protein folding and cell structure maintenance decreased. Flooding induced changes of phosphorylation status of proteins involved in energy generation, protein synthesis and cell structure maintenance. The response to flooding stress may be regulated by both modulation of protein expression and phosphorylation state. Energy-demanding and production-related metabolic pathways may be particularly subject to regulation by changes in protein phosphorylation during flooding. 相似文献
50.
In a study of the responses of photosystem II (PSII) to high temperature in suspension-cultured cells of soybean (Glycine max L. Merr.), we found that high temperatures inactivated PSII via two distinct pathways. Inactivation of PSII by moderately
high temperatures, such as 41°C, was reversed upon transfer of cells to 25°C. The recovery of PSII required light, but not
the synthesis of proteins de novo. By contrast, temperatures higher than 45°C inactivated PSII irreversibly. An increase in
the growth temperature from 25 to 35°C resulted in an upward shift of 3°C in the profile of the heat-induced inactivation
of PSII, which indicated that the thermal stability of PSII had been enhanced. This acclimative response was reflected by
the properties of isolated thylakoid membranes: PSII in thylakoid membranes from cells that had been grown at 35°C exhibited
greater thermal stability than that from cells grown at 25°C. Disruption of the vesicular structure of thylakoid membranes
with 0.05% Triton X-100 decreased the thermal stability of PSII to a similar level in both types of thylakoid membrane. Proteins
released by Triton X-100 from thylakoid membranes from cells grown at 35°C were able to increase the thermal stability of
Triton-treated thylakoid membranes. These observations suggest that proteins that are associated with thylakoid membranes
might be involved in the enhancement of the thermal stability of PSII. 相似文献