Degenerate primers were designed based on the conserved sequences of the Actin gene from other plants. Total RNA was extracted from the leaves of lris lacteal var.chinensis Fisch.Koidz. Actin gene fragment was obtaine...Degenerate primers were designed based on the conserved sequences of the Actin gene from other plants. Total RNA was extracted from the leaves of lris lacteal var.chinensis Fisch.Koidz. Actin gene fragment was obtained by reverse transcription polymerase chain reaction （RT-PCR） and cloned into pMD18-T vector. The positive clone identified by PCR was sequenced. The sequencing result showed that the Actin gene fragment from lris lacteal var.chinensis Fisch.Koidz contained about 598 bp, encoding 199 amino acids. Homology comparison with Actin gene sequences of other plants in the GenBank showed that it shared over 82% nueleotide sequence homology and 90% amino acid sequence homology. It indicated that this was the Actin gene. Because of the stability expression ofActin gene, it usually cited as the internal reference to study the expression and regulation of foundation in other genes of lris lacteal var.chinensis Fisch.Koidz well.展开更多
Chinese iris （Iris lactea Pall. var. chinensis （Fisch） Koidz.）, a robust iridaceous plant, is widespread in arid and semiarid regions with high salinity. However, the mechanism of its salt tolerance is not well un...Chinese iris （Iris lactea Pall. var. chinensis （Fisch） Koidz.）, a robust iridaceous plant, is widespread in arid and semiarid regions with high salinity. However, the mechanism of its salt tolerance is not well understood. In this study, plant growth, water status, content and distribution of inorganic ions, cell membrane permeability, and proline content of I. laetea under salt stress were investigated using nutrient solutions with six NaCl concentrations ranging from 0 to 350 mmol L^-1. The results indicated that the biomass, height, fresh weight, K^＋ content, and K^＋/Na^＋ and Ca^2＋/Na^＋ ratios decreased with increasing NaCl stress, whereas plant water deficit and contents of Na^＋ and Cl- increased with increasing NaCl stress. In all salt treatments, water deficit of shoots was found to be higher than that of roots and had a positive correlation with salt concentration. When the NaCl concentration was less than 280 mmol L^-1, the ion absorption selectivity ratio and the transportation selectivity ratio sharply increased with increasing NaCl stress. Under medium salt stress, I. lactea exhibited a strong K^＋ selective absorption and the transportation of K^＋ from roots to shoots increased, whereas Na^＋ was not transported and was mostly retained in roots. The plants were able to maintain osmotic adjustment through the accumulation of Na^＋, Cl-, and proline. On the basis of its biomass production under salt stress, I. lactea could be considered as a facultative halophyte.展开更多
Maintenance of ion homeostasis,particularly the regulation of K^(+)and Na^(+)uptake,is important for all plants to adapt to salinity.Observations on ionic response to salinity and net fluxes of K^(+),Na^(+)in the root...Maintenance of ion homeostasis,particularly the regulation of K^(+)and Na^(+)uptake,is important for all plants to adapt to salinity.Observations on ionic response to salinity and net fluxes of K^(+),Na^(+)in the root exhibited by plants during salt stress have highlighted the need for further investigation.The objectives of this study were to compare salt adaptation of two Chinese Iris(Iris lactea Pall.var.chinensis(Fisch.)Koidz.)populations,and to improve understanding of adaptation to salinity exhibited by plants.Plants used in this study were grown from seeds collected in the Xinjiang Uygur Autonomous Region(Xj)and Beijing Municipality(Bj),China.Hydroponicallygrown seedlings of the two populations were supplied with nutrient solutions containing 0.1(control)and 140 mmol·L^(–1) NaCl.After 12 days,plants were harvested for determination of relative growth rate and K^(+),Na^(+)concentrations.Net fluxes of K^(+),Na^(+)from the apex and along the root axis to 10.8 mm were measured using noninvasive micro-test technique.With 140 mmol·L^(–1) NaCl treatment,shoots for population Xj had larger relative growth rate and higher K^(+)concentration than shoots for population Bj.However,the Na^(+)concentrations in both shoots and roots were lower for Xj than those for Bj.There was a lower net efflux of K^(+)found in population Xj than by Bj in the mature zone(approximately 2.4^(–1)0.8 mm from root tip).However,no difference in the efflux of Na^(+)between the populations was obtained.Population Xj of I.lactea continued to grow normally under NaCl stress,and maintained a higher K^(+)/Na^(+)ratio in the shoots.These traits,which were associated with lower K^(+)leakage,help population Xj adapt to saline environments.展开更多
基金Supported by the Postdoctoral Scientific Research Foundation of Heilongjiang Province(LBH-Q10144)the Natural Science Foundation of Heilongjiang Province(C201112)Northeast Agricultural University Doctoral Research Fund(200830)
文摘Degenerate primers were designed based on the conserved sequences of the Actin gene from other plants. Total RNA was extracted from the leaves of lris lacteal var.chinensis Fisch.Koidz. Actin gene fragment was obtained by reverse transcription polymerase chain reaction （RT-PCR） and cloned into pMD18-T vector. The positive clone identified by PCR was sequenced. The sequencing result showed that the Actin gene fragment from lris lacteal var.chinensis Fisch.Koidz contained about 598 bp, encoding 199 amino acids. Homology comparison with Actin gene sequences of other plants in the GenBank showed that it shared over 82% nueleotide sequence homology and 90% amino acid sequence homology. It indicated that this was the Actin gene. Because of the stability expression ofActin gene, it usually cited as the internal reference to study the expression and regulation of foundation in other genes of lris lacteal var.chinensis Fisch.Koidz well.
基金the National Natural Science Foundation of China (No.30170671).
文摘Chinese iris （Iris lactea Pall. var. chinensis （Fisch） Koidz.）, a robust iridaceous plant, is widespread in arid and semiarid regions with high salinity. However, the mechanism of its salt tolerance is not well understood. In this study, plant growth, water status, content and distribution of inorganic ions, cell membrane permeability, and proline content of I. laetea under salt stress were investigated using nutrient solutions with six NaCl concentrations ranging from 0 to 350 mmol L^-1. The results indicated that the biomass, height, fresh weight, K^＋ content, and K^＋/Na^＋ and Ca^2＋/Na^＋ ratios decreased with increasing NaCl stress, whereas plant water deficit and contents of Na^＋ and Cl- increased with increasing NaCl stress. In all salt treatments, water deficit of shoots was found to be higher than that of roots and had a positive correlation with salt concentration. When the NaCl concentration was less than 280 mmol L^-1, the ion absorption selectivity ratio and the transportation selectivity ratio sharply increased with increasing NaCl stress. Under medium salt stress, I. lactea exhibited a strong K^＋ selective absorption and the transportation of K^＋ from roots to shoots increased, whereas Na^＋ was not transported and was mostly retained in roots. The plants were able to maintain osmotic adjustment through the accumulation of Na^＋, Cl-, and proline. On the basis of its biomass production under salt stress, I. lactea could be considered as a facultative halophyte.
基金This work was supported financially by the National Natural Science Foundation of China(31370351 and 30870237)the Doctoral Program of Higher Education of the Special Research Doctoral Advisor Fund of China(20110008110035).
文摘Maintenance of ion homeostasis,particularly the regulation of K^(+)and Na^(+)uptake,is important for all plants to adapt to salinity.Observations on ionic response to salinity and net fluxes of K^(+),Na^(+)in the root exhibited by plants during salt stress have highlighted the need for further investigation.The objectives of this study were to compare salt adaptation of two Chinese Iris(Iris lactea Pall.var.chinensis(Fisch.)Koidz.)populations,and to improve understanding of adaptation to salinity exhibited by plants.Plants used in this study were grown from seeds collected in the Xinjiang Uygur Autonomous Region(Xj)and Beijing Municipality(Bj),China.Hydroponicallygrown seedlings of the two populations were supplied with nutrient solutions containing 0.1(control)and 140 mmol·L^(–1) NaCl.After 12 days,plants were harvested for determination of relative growth rate and K^(+),Na^(+)concentrations.Net fluxes of K^(+),Na^(+)from the apex and along the root axis to 10.8 mm were measured using noninvasive micro-test technique.With 140 mmol·L^(–1) NaCl treatment,shoots for population Xj had larger relative growth rate and higher K^(+)concentration than shoots for population Bj.However,the Na^(+)concentrations in both shoots and roots were lower for Xj than those for Bj.There was a lower net efflux of K^(+)found in population Xj than by Bj in the mature zone(approximately 2.4^(–1)0.8 mm from root tip).However,no difference in the efflux of Na^(+)between the populations was obtained.Population Xj of I.lactea continued to grow normally under NaCl stress,and maintained a higher K^(+)/Na^(+)ratio in the shoots.These traits,which were associated with lower K^(+)leakage,help population Xj adapt to saline environments.
