Brassica chinensis L. were foliarly applied with glycinebetaine (GB), as this species is unable to synthesis GB and sensitive to osmotic stress such as salt. The exogenous GB was easily absorbed and transported by t...Brassica chinensis L. were foliarly applied with glycinebetaine (GB), as this species is unable to synthesis GB and sensitive to osmotic stress such as salt. The exogenous GB was easily absorbed and transported by the leaf of B. chinensis . Its application (0-20 mmol/L) enhanced the plant tolerance to salt stress. The treatment of 15 mmol/L GB significantly decreased the Na + accumulation in leaf and root under NaCl stress. This difference in accumulating Na + and K + is caused by higher selectivity of root absorption. Furthermore, GB increased H +_ATPase activity of root plasma membrane evidently. This result strongly suggested that in root the decreased Na + accumulation was caused by the GB accumulation that enhanced the extrusion of Na + from the cell in some way through plasma membrane transporter, e.g. Na +/H + antiport driven by H +_ATPase. The GB application was also found to stabilize the plasma membrane, to decrease the loss of chlorophyll, and to stimulate the osmosis induced proline response under salt stress.展开更多
Glycinebetaine （Glybet） accumulation, photosynthetic efficiency and growth performance in indica rice cultivated under salt stress and extreme pH stress were investigated. Betaine aldehyde dehydrogenase （BADH） act...Glycinebetaine （Glybet） accumulation, photosynthetic efficiency and growth performance in indica rice cultivated under salt stress and extreme pH stress were investigated. Betaine aldehyde dehydrogenase （BADH） activity and Glybet accumulation in the seedlings of salt-tolerant and salt-sensitive rice varieties grown under saline and acidic conditions peaked after treatment for 72 h and 96 h, respectively, and were higher than those grown under neutral pH and alkaline salt stress. A positive correlation was found between BADH activity and Glybet content in both salt-tolerant （P=0.71） and salt-sensitive （P=0.86） genotypes. The chlorophyll a, chlorophyll b, total chlorophyll and total carotenoids contents in the stressed seedlings significantly decreased under both acidic and alkaline stresses, especially in the salt-sensitive genotype. Similarly, the maximum quantum yield of PSII （Fv/Fm）, photon yield of PSII （ФPSII）, non-photochemical quenching （NPQ） and net photosynthetic rate （Pn） in the stressed seedlings were inhibited, leading to overall growth reduction. The positive correlations between chlorophyll a content and Fv/Fm, total chlorophyll content and ФPSII, and Pn as well as Pn and leaf area in both salt-tolerant and salt-sensitive genotypes were found. Saline acidic and saline alkaline soils may play a key role affecting vegetative growth prior to the reproductive stage in rice plants.展开更多
Although exogenous application of glycinebetaine(GB) is widely reported to regulate a myriad of physio-biochemical attributes in plants under stressful environments including drought stress, there is little informatio...Although exogenous application of glycinebetaine(GB) is widely reported to regulate a myriad of physio-biochemical attributes in plants under stressful environments including drought stress, there is little information available in the literature on how and up to what extent GB can induce changes in anatomical features in water starved plants. Thus, the present research work was conducted to assess the GB-induced changes in growth, physio-biochemical, and anatomical characteristics in two cultivars(CK-1 and F-411) of oat(Avena sativa L.) under limited water supply. After exposure to water stress, a considerable reduction was observed in plant growth in terms of lengths and weights of shoot and roots,leaf mesophyll thickness, leaf midrib thickness, root cortex thickness, root diameter, stem diameter, stem phloem area, and stem vascular bundle area in both oat cultivars. However, water stress resulted in a significant increase in leaf total phenolics, hydrogen peroxide(H_2 O_2), ascorbic acid(AsA), GB contents,activities of enzymes(CAT, SOD and POD), total soluble proteins, leaf epidermis(abaxial and adaxial)thickness, bulliform cell area, sclerenchyma thickness, root endodermis and epidermis thickness, root metaxylem area, stem metaxylem area and stem sclerenchyma thickness in both oat cultivars.Foliar-applied 100 mM GB suppressed H_2 O_2 contents, while improved growth attributes, free proline and GB contents, activity of SOD enzyme, leaf abaxial epidermis thickness, leaf bulliform cell area, leaf midrib thickness, leaf sclerenchyma thickness, root cortex thickness, root endodermis, epidermis thickness,root stele diameter, stem diameter, stem epidermis thickness, stem metaxylem area, and stem phloem and vascular bundle area in both oat cultivars. For both oat cultivars, CK-1 was superior to F-411 in leaf abaxial epidermis thickness, leaf mesophyll, leaf sclerenchyma, root metaxylem area, stem diameter, stem epidermis, sclerenchyma thickness, stem metaxylem area, and stem vascular bundle area. Overall, both oat cultivars showed inconsistent behavior to water stress and foliar-applied GB in terms of different physio-biochemical attributes, however, CK-1 was superior to F-411 in a number of anatomical features of leaf, root, and stem.展开更多
A pot experiment was conducted under water deficit and adequate water-supplied conditions with two maize genetypic varieties （Shaandan 9 and Shaandan 911） to study the effects of nitrogen, potassium and glycinebetai...A pot experiment was conducted under water deficit and adequate water-supplied conditions with two maize genetypic varieties （Shaandan 9 and Shaandan 911） to study the effects of nitrogen, potassium and glycinebetaine （GlyBet） on the dry matter and grain yields as well as water use efficiency （WUE）. Determinations were made at different stages of the two varieties for revealing the function of these factors in increasing plant resistance to drought. Results showed that under a water-stressed condition, dry matter and grain yield were significantly reduced. However, the response of the two varieties to water stress was different： Shaandan 9 was significantly higher in dry matter and grain yields, and therefore could be regarded as a drought-resistant variety compared to Shaandan 911.Application of nitrogen, potassium and glycinebetaine raised dry matter and grain yield to different levels, and thereby alleviated the water stress and increased water use efficiency. These effects were higher for Shaandan 911 than for Shaandan 9. Under water-stressed conditions application of N fertilizer, either at low rate or at high rate, significantly increased dry matter, grain yield and water use efficiency. A significant different effect was found for Shaandan 911 between N rates, but not so for Shaandan 9. However, with supplemental water supply, effects of N fertilization were obviously decreased, showing that in addition to supplying nutrient, N fertilizer has a function in increasing drought-resistance of the crop. Potassium and glycinebetaine exhibited a remarkable function in increasing dry matter and grain yields as well as water use efficiency under water stress while such effects were obviously declined, even vanished, with supplemental water supply, indicating the important contribution of these factors in rise of drought-resistance ability of a crop.展开更多
PHOTOSYSTEM Ⅱ（PS Ⅱ） particles capable of O<sub>2</sub> evolution contain D1, D2 transmembrane pro-teins, and three extrinsic polypeptides which are exposed to the outer aqueous phase with ap-parent mol...PHOTOSYSTEM Ⅱ（PS Ⅱ） particles capable of O<sub>2</sub> evolution contain D1, D2 transmembrane pro-teins, and three extrinsic polypeptides which are exposed to the outer aqueous phase with ap-parent molecular masses of 33, 23, 18 kD. The three proteins can be partially or totally re-moved by treating the PS Ⅱ membranes with high concentrations of salt or other methods,展开更多
The effect of glycinebetaine in selectively stabilizing the PSII extrinsic polypeptides was studied with PSII particles treated with different methods. It was shown that glycinebetaine markedly stabilized the PSII ext...The effect of glycinebetaine in selectively stabilizing the PSII extrinsic polypeptides was studied with PSII particles treated with different methods. It was shown that glycinebetaine markedly stabilized the PSII extrinsic polypeptides when the particles were treated with 0.8 mol/L Tris (pH8.0) or high concentrations of NaCl. The stabilizing effect was less pronounced when the PSII particles were treated by heat shock or trichloroacetate (TCA). The capability of halogenated acetates to release extrinsic polypeptides in PSII particles was found to follow the order of decreasing molecular hydrophobicities: trichloroacetate (TCA)> dichloroacetate (DCA)> monoiodoacetate (MIA)>monobromoacetate (MBA)>monochloroacetate (MCA). All these results imply that glycinebetaine is effective in stabilizing biopolymer structure against the action of electrolytes, while it is ineffective in protecting extrinsic polypeptides in PSII particles from dissociation induced by halogenated acetates or heat treatments which disturbed the hydrophobic interactions within the polypeptides.展开更多
文摘Brassica chinensis L. were foliarly applied with glycinebetaine (GB), as this species is unable to synthesis GB and sensitive to osmotic stress such as salt. The exogenous GB was easily absorbed and transported by the leaf of B. chinensis . Its application (0-20 mmol/L) enhanced the plant tolerance to salt stress. The treatment of 15 mmol/L GB significantly decreased the Na + accumulation in leaf and root under NaCl stress. This difference in accumulating Na + and K + is caused by higher selectivity of root absorption. Furthermore, GB increased H +_ATPase activity of root plasma membrane evidently. This result strongly suggested that in root the decreased Na + accumulation was caused by the GB accumulation that enhanced the extrusion of Na + from the cell in some way through plasma membrane transporter, e.g. Na +/H + antiport driven by H +_ATPase. The GB application was also found to stabilize the plasma membrane, to decrease the loss of chlorophyll, and to stimulate the osmosis induced proline response under salt stress.
基金supported by the National Center for Genetic Engineering and Biotechnology (BIOTEC) (Grant No. BT-B-06-RG-14-4502)partly funded by the International Atomic Energy Agency (IAEA) (Contract No. 12998/R0)
文摘Glycinebetaine （Glybet） accumulation, photosynthetic efficiency and growth performance in indica rice cultivated under salt stress and extreme pH stress were investigated. Betaine aldehyde dehydrogenase （BADH） activity and Glybet accumulation in the seedlings of salt-tolerant and salt-sensitive rice varieties grown under saline and acidic conditions peaked after treatment for 72 h and 96 h, respectively, and were higher than those grown under neutral pH and alkaline salt stress. A positive correlation was found between BADH activity and Glybet content in both salt-tolerant （P=0.71） and salt-sensitive （P=0.86） genotypes. The chlorophyll a, chlorophyll b, total chlorophyll and total carotenoids contents in the stressed seedlings significantly decreased under both acidic and alkaline stresses, especially in the salt-sensitive genotype. Similarly, the maximum quantum yield of PSII （Fv/Fm）, photon yield of PSII （ФPSII）, non-photochemical quenching （NPQ） and net photosynthetic rate （Pn） in the stressed seedlings were inhibited, leading to overall growth reduction. The positive correlations between chlorophyll a content and Fv/Fm, total chlorophyll content and ФPSII, and Pn as well as Pn and leaf area in both salt-tolerant and salt-sensitive genotypes were found. Saline acidic and saline alkaline soils may play a key role affecting vegetative growth prior to the reproductive stage in rice plants.
基金financially supported by the Department of Botany, Government College University, Faisalabad, Pakistan
文摘Although exogenous application of glycinebetaine(GB) is widely reported to regulate a myriad of physio-biochemical attributes in plants under stressful environments including drought stress, there is little information available in the literature on how and up to what extent GB can induce changes in anatomical features in water starved plants. Thus, the present research work was conducted to assess the GB-induced changes in growth, physio-biochemical, and anatomical characteristics in two cultivars(CK-1 and F-411) of oat(Avena sativa L.) under limited water supply. After exposure to water stress, a considerable reduction was observed in plant growth in terms of lengths and weights of shoot and roots,leaf mesophyll thickness, leaf midrib thickness, root cortex thickness, root diameter, stem diameter, stem phloem area, and stem vascular bundle area in both oat cultivars. However, water stress resulted in a significant increase in leaf total phenolics, hydrogen peroxide(H_2 O_2), ascorbic acid(AsA), GB contents,activities of enzymes(CAT, SOD and POD), total soluble proteins, leaf epidermis(abaxial and adaxial)thickness, bulliform cell area, sclerenchyma thickness, root endodermis and epidermis thickness, root metaxylem area, stem metaxylem area and stem sclerenchyma thickness in both oat cultivars.Foliar-applied 100 mM GB suppressed H_2 O_2 contents, while improved growth attributes, free proline and GB contents, activity of SOD enzyme, leaf abaxial epidermis thickness, leaf bulliform cell area, leaf midrib thickness, leaf sclerenchyma thickness, root cortex thickness, root endodermis, epidermis thickness,root stele diameter, stem diameter, stem epidermis thickness, stem metaxylem area, and stem phloem and vascular bundle area in both oat cultivars. For both oat cultivars, CK-1 was superior to F-411 in leaf abaxial epidermis thickness, leaf mesophyll, leaf sclerenchyma, root metaxylem area, stem diameter, stem epidermis, sclerenchyma thickness, stem metaxylem area, and stem vascular bundle area. Overall, both oat cultivars showed inconsistent behavior to water stress and foliar-applied GB in terms of different physio-biochemical attributes, however, CK-1 was superior to F-411 in a number of anatomical features of leaf, root, and stem.
基金The study was supported by the key project(30230230)general project(30070429)of National Natural Science Foundation of China(NSFC).The authors would like to take the opportunity to thank the NSFC for its kindness to support such projects.
文摘A pot experiment was conducted under water deficit and adequate water-supplied conditions with two maize genetypic varieties （Shaandan 9 and Shaandan 911） to study the effects of nitrogen, potassium and glycinebetaine （GlyBet） on the dry matter and grain yields as well as water use efficiency （WUE）. Determinations were made at different stages of the two varieties for revealing the function of these factors in increasing plant resistance to drought. Results showed that under a water-stressed condition, dry matter and grain yield were significantly reduced. However, the response of the two varieties to water stress was different： Shaandan 9 was significantly higher in dry matter and grain yields, and therefore could be regarded as a drought-resistant variety compared to Shaandan 911.Application of nitrogen, potassium and glycinebetaine raised dry matter and grain yield to different levels, and thereby alleviated the water stress and increased water use efficiency. These effects were higher for Shaandan 911 than for Shaandan 9. Under water-stressed conditions application of N fertilizer, either at low rate or at high rate, significantly increased dry matter, grain yield and water use efficiency. A significant different effect was found for Shaandan 911 between N rates, but not so for Shaandan 9. However, with supplemental water supply, effects of N fertilization were obviously decreased, showing that in addition to supplying nutrient, N fertilizer has a function in increasing drought-resistance of the crop. Potassium and glycinebetaine exhibited a remarkable function in increasing dry matter and grain yields as well as water use efficiency under water stress while such effects were obviously declined, even vanished, with supplemental water supply, indicating the important contribution of these factors in rise of drought-resistance ability of a crop.
文摘PHOTOSYSTEM Ⅱ（PS Ⅱ） particles capable of O<sub>2</sub> evolution contain D1, D2 transmembrane pro-teins, and three extrinsic polypeptides which are exposed to the outer aqueous phase with ap-parent molecular masses of 33, 23, 18 kD. The three proteins can be partially or totally re-moved by treating the PS Ⅱ membranes with high concentrations of salt or other methods,
文摘The effect of glycinebetaine in selectively stabilizing the PSII extrinsic polypeptides was studied with PSII particles treated with different methods. It was shown that glycinebetaine markedly stabilized the PSII extrinsic polypeptides when the particles were treated with 0.8 mol/L Tris (pH8.0) or high concentrations of NaCl. The stabilizing effect was less pronounced when the PSII particles were treated by heat shock or trichloroacetate (TCA). The capability of halogenated acetates to release extrinsic polypeptides in PSII particles was found to follow the order of decreasing molecular hydrophobicities: trichloroacetate (TCA)> dichloroacetate (DCA)> monoiodoacetate (MIA)>monobromoacetate (MBA)>monochloroacetate (MCA). All these results imply that glycinebetaine is effective in stabilizing biopolymer structure against the action of electrolytes, while it is ineffective in protecting extrinsic polypeptides in PSII particles from dissociation induced by halogenated acetates or heat treatments which disturbed the hydrophobic interactions within the polypeptides.
