Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ‘Gold Mound＇ and Spiraea × ...Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ‘Gold Mound＇ and Spiraea × bumalda ‘Gold Flame＇. The present study aimed at exploring the antioxidant capacity in roots of spiraeas and revealing their adaptability to salt-alkali stress. Results indicate that the oxygen free radicals contents, electrolyte leakage rates and MDA contents in roots of Spiraea × bumalda ＇Gold Mound＇ and Spiraea × bumalda ＇Gold Flame＇ show an increasing tendency with the increases of the salinity and pH value, whereas the activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） all increased firstly and then decreased. With the increase in intensity of salt-alkali stress, the CAT activity in roots of Spiraea × bumalda ‘Gold Flame＇ is higher and the increasing extents in the oxygen free radicals contents, electrolyte leakage rates as well as MDA contents are lower compared with Spiraea × bumalda ‘Gold Mound＇, indicating that Spiraea × bumalda ‘Gold Flame＇ has a stronger antioxidant capacity.展开更多
Seed germination and early seedling growth are crucial stages for plant establishment. Two neutral(Na Cl and Na2SO4) and two alkali(Na HCO3 and Na2CO3) salts were selected to investigate their effects on germination a...Seed germination and early seedling growth are crucial stages for plant establishment. Two neutral(Na Cl and Na2SO4) and two alkali(Na HCO3 and Na2CO3) salts were selected to investigate their effects on germination and recovery responses in Reaumuria soongorica. Results show that both salt types significantly reduced germination and radicle elongation. The rate of germination and emergence of R. soongorica seeds continuously decreased as salinity increased, and the time to achieve maximum germination rate was delayed. The speed of seed germination dropped rapidly as salt concentration increased.Alkaline salts restricted the germination rate of R. soongorica seeds, and stresses resulting from alkaline salts and high concentrations of neutral salts resulted in many deformed seedlings. The length of the radicle and germ decreased with increasing salt concentration, but certain concentrations of salt and increased p H promoted germ growth. The results of regression analysis show that salt concentration was the dominant factor inhibiting R. soongorica seed germination rate. Salinity, buffering capacity, and p H all affected embryo growth, but salinity had the most pronounced effect. Seed viability under highly saline conditions appears to be a better indicator of adaptation to saline environments than seed germination under saline conditions.展开更多
The effects of neutral salt and alkali on the ion distribution were investigated in two alfalfa （Medicago sativa L.） cultivars, including Zhongmu 1, a high salt-tolerant cultivar, and Algonquin, a low salt-tolerant ...The effects of neutral salt and alkali on the ion distribution were investigated in two alfalfa （Medicago sativa L.） cultivars, including Zhongmu 1, a high salt-tolerant cultivar, and Algonquin, a low salt-tolerant cultivar. The alkali stress expressed more serious growth inhibition than the neutral salt stress at the same Na＋ concentration. Compared with Algonquin, Zhongmu 1 did not exhibit a higher alkali tolerance under the Na2CO3-NaHCO3 treatment with the low Na＋ concentration （50 mmol L-l）. The alkali increased the accumulation of Na＋, Ca2＋, and Mg2＋ in the root and changed the Ca2＋ and Mg2＋ balance in the entire alfalfa plant. The salt and alkali stresses decreased the K＋ and Fe3＋ contents of the roots and leaves, the root Mn2＋ content, and the shoot Zn2＋ content, but they increased the Fe3＋ accumulation of the shoots, the shoot and leaf Cu2＋ contents, and the leaf Zn2＋ content in both alfalfa cultivars. Based on the results obtained under the conditions of this experiment, we found that the salt and alkali stresses reduced the plant growth in both alfalfa cultivars, while the alkali caused a stronger stress than the neutral salt in alfalfa. Thus, we conclude that under hydroponic conditions, the deleterious effects of the alkali on plants are due to the distribution change of some trophic ion balance in the roots, shoots, and leaves of the plants by causing of Na＋, CO3^2-, and/or HCO3- stresses.展开更多
Saline-alkaline stress can dramatically inhibit plant growth and limit crop production. Wild soybean （Glycine soja） is a crop that adapts well to such environmental stresses. In this study, RNA-sequencing technology...Saline-alkaline stress can dramatically inhibit plant growth and limit crop production. Wild soybean （Glycine soja） is a crop that adapts well to such environmental stresses. In this study, RNA-sequencing technology was used to analyze the transcriptome profles of G. soja roots subjected to 50 mmol·L^-1 NaHCO3 and 150 mmol·L^-1 NaCl treatments. Totally, 2 125 differentially-expressed genes （DEGs） after NaCl treatment and 1 839 DEGs after NaHCO3 treatment were identifed. The top 14 DEGs revealed by RNA-seq were analyzed using qRT-PCR （quantitative real-time polymerase chain reaction）. Gene ontology （GO） annotation showed that most of DEGs under salt and alkali stresses were enriched in ＂metabolic process＂, ＂catalytic activity＂ and ＂binding＂ terms. To search for transcription factors （TFs） among DEGs, the data were screened against TF database PlantTFDB, and it was found that fve TF families, Apetala2/ethylene-responsive element binding proteins （AP2-EREBP）, V-myb avian myeloblastosis viral oncogene homolog （MYB）, WRKYGQK and Zinc fnger motif （WRKY）, NAM, ATAF1/2, CUC1/2 （NAC） and Cys2/His2 （C2H2） were involved in salt stress response. Other fve TF families, NAC, WRKY, MYB, AP2-EREBP and bZIP were involved in response to alkali stress. These two stress treatments shared NAC, WRKY, AP2-EREBP and MYB, and the only two different TFs were bZIP and C2H2. Forty-eight MYB TFs were differentially expressed under salt and alkali stresses, and most of them were up-regulated. This study provided useful information for further investigation of DEGs and TFs in response to saline and alkaline stresses and helped in understanding the molecular basis of the response of G. soja to saline and alkaline stresses.展开更多
基金supported by Innovation Team Project of Northeast Agricultural University of P. R. China (CXZ004-3)Science Foundation of Heilongjiang Province (C2007-16)
文摘Under artificially-simulated complex salt-alkali stress, the levels of active oxygen metabolism in roots were studied using three-year-old cutting seedlings of Spiraea × bumalda ‘Gold Mound＇ and Spiraea × bumalda ‘Gold Flame＇. The present study aimed at exploring the antioxidant capacity in roots of spiraeas and revealing their adaptability to salt-alkali stress. Results indicate that the oxygen free radicals contents, electrolyte leakage rates and MDA contents in roots of Spiraea × bumalda ＇Gold Mound＇ and Spiraea × bumalda ＇Gold Flame＇ show an increasing tendency with the increases of the salinity and pH value, whereas the activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） all increased firstly and then decreased. With the increase in intensity of salt-alkali stress, the CAT activity in roots of Spiraea × bumalda ‘Gold Flame＇ is higher and the increasing extents in the oxygen free radicals contents, electrolyte leakage rates as well as MDA contents are lower compared with Spiraea × bumalda ‘Gold Mound＇, indicating that Spiraea × bumalda ‘Gold Flame＇ has a stronger antioxidant capacity.
基金supported by the National Natural Science Foundation of China (41401043, 91125025)
文摘Seed germination and early seedling growth are crucial stages for plant establishment. Two neutral(Na Cl and Na2SO4) and two alkali(Na HCO3 and Na2CO3) salts were selected to investigate their effects on germination and recovery responses in Reaumuria soongorica. Results show that both salt types significantly reduced germination and radicle elongation. The rate of germination and emergence of R. soongorica seeds continuously decreased as salinity increased, and the time to achieve maximum germination rate was delayed. The speed of seed germination dropped rapidly as salt concentration increased.Alkaline salts restricted the germination rate of R. soongorica seeds, and stresses resulting from alkaline salts and high concentrations of neutral salts resulted in many deformed seedlings. The length of the radicle and germ decreased with increasing salt concentration, but certain concentrations of salt and increased p H promoted germ growth. The results of regression analysis show that salt concentration was the dominant factor inhibiting R. soongorica seed germination rate. Salinity, buffering capacity, and p H all affected embryo growth, but salinity had the most pronounced effect. Seed viability under highly saline conditions appears to be a better indicator of adaptation to saline environments than seed germination under saline conditions.
基金supported financially by the Open Project of the National Key Laboratory for Grassland Agro-ecosytems hosted at Lanzhou University,Chinathe construction project of Key Discipline of Jiangsu Province for grass science,China
文摘The effects of neutral salt and alkali on the ion distribution were investigated in two alfalfa （Medicago sativa L.） cultivars, including Zhongmu 1, a high salt-tolerant cultivar, and Algonquin, a low salt-tolerant cultivar. The alkali stress expressed more serious growth inhibition than the neutral salt stress at the same Na＋ concentration. Compared with Algonquin, Zhongmu 1 did not exhibit a higher alkali tolerance under the Na2CO3-NaHCO3 treatment with the low Na＋ concentration （50 mmol L-l）. The alkali increased the accumulation of Na＋, Ca2＋, and Mg2＋ in the root and changed the Ca2＋ and Mg2＋ balance in the entire alfalfa plant. The salt and alkali stresses decreased the K＋ and Fe3＋ contents of the roots and leaves, the root Mn2＋ content, and the shoot Zn2＋ content, but they increased the Fe3＋ accumulation of the shoots, the shoot and leaf Cu2＋ contents, and the leaf Zn2＋ content in both alfalfa cultivars. Based on the results obtained under the conditions of this experiment, we found that the salt and alkali stresses reduced the plant growth in both alfalfa cultivars, while the alkali caused a stronger stress than the neutral salt in alfalfa. Thus, we conclude that under hydroponic conditions, the deleterious effects of the alkali on plants are due to the distribution change of some trophic ion balance in the roots, shoots, and leaves of the plants by causing of Na＋, CO3^2-, and/or HCO3- stresses.
基金Supported by the National Science Foundation of China(31771692)Major Project on Breeding of New Varieties of Genetically Modified Organisms(2011ZX08004-002)
文摘Saline-alkaline stress can dramatically inhibit plant growth and limit crop production. Wild soybean （Glycine soja） is a crop that adapts well to such environmental stresses. In this study, RNA-sequencing technology was used to analyze the transcriptome profles of G. soja roots subjected to 50 mmol·L^-1 NaHCO3 and 150 mmol·L^-1 NaCl treatments. Totally, 2 125 differentially-expressed genes （DEGs） after NaCl treatment and 1 839 DEGs after NaHCO3 treatment were identifed. The top 14 DEGs revealed by RNA-seq were analyzed using qRT-PCR （quantitative real-time polymerase chain reaction）. Gene ontology （GO） annotation showed that most of DEGs under salt and alkali stresses were enriched in ＂metabolic process＂, ＂catalytic activity＂ and ＂binding＂ terms. To search for transcription factors （TFs） among DEGs, the data were screened against TF database PlantTFDB, and it was found that fve TF families, Apetala2/ethylene-responsive element binding proteins （AP2-EREBP）, V-myb avian myeloblastosis viral oncogene homolog （MYB）, WRKYGQK and Zinc fnger motif （WRKY）, NAM, ATAF1/2, CUC1/2 （NAC） and Cys2/His2 （C2H2） were involved in salt stress response. Other fve TF families, NAC, WRKY, MYB, AP2-EREBP and bZIP were involved in response to alkali stress. These two stress treatments shared NAC, WRKY, AP2-EREBP and MYB, and the only two different TFs were bZIP and C2H2. Forty-eight MYB TFs were differentially expressed under salt and alkali stresses, and most of them were up-regulated. This study provided useful information for further investigation of DEGs and TFs in response to saline and alkaline stresses and helped in understanding the molecular basis of the response of G. soja to saline and alkaline stresses.
