The differences of glucose-6P dehydrogenase (G6PDH) activity and freezing resistance induced by freezing acclimation between cuttings of freezing-sensitive P. tomentosa and freezing-resistant P. suaveolens were compar...The differences of glucose-6P dehydrogenase (G6PDH) activity and freezing resistance induced by freezing acclimation between cuttings of freezing-sensitive P. tomentosa and freezing-resistant P. suaveolens were compared for exploring the role of G6PDH on the enhancement of freezing resistance induced by freezing acclimation. After 5 d of freezing acclimation at -3 ℃, the LT50 of P. tomentosa has decreased from -6.2 ℃ in control cuttings to -14.3 ℃ in freezing acclimated ones, and the increase of G6PDH activity was observed in freezing acclimated cuttings as compared with control ones. Whereas, when P. suaveolens was freezing acclimated at -20℃ for 5 d, the LT50 has decreased from -27.1℃ in control cuttings to -43.5 ℃ in freezing acclimated ones, and the activity of G6PDH increased considerably. In addition, the increase of LT50 and the decrease of G6PDH activity resulting from 2 d of deacclimation at 25 ℃ were found in two kinds of freezing acclimated cuttings. It is concluded that the increase in the activity of G6PDH may associate with the inherited freezing resistance of species and the enhancement of freezing resistance of cuttings, and may play an important role in the antifreeze process under freezing temperature, which would provide the basis for the study on the molecular mechanism of freezing resistance in P. suaveolens and the cloning of gene associated with freezing resistance.展开更多
Alpine plants possess unique traits to adapt alpine environments.Whether leaf trait relationships of alpine plants can be captured by the two trait dimensions of organ size and resource economics is unknown.We hypothe...Alpine plants possess unique traits to adapt alpine environments.Whether leaf trait relationships of alpine plants can be captured by the two trait dimensions of organ size and resource economics is unknown.We hypothesized that,beyond the trait dimensions of leaf size and resource economics,nonstructured carbohydrates(NSC)would reflect a dimension of cold-tolerance in alpine plants.To test this hypothesis,we measured 12 leaf traits critical to leaf construction and growth in 143 species across 7 sites ranging from alpine steppes to alpine meadows along an environmental gradient on the Tibetan Plateau.Furthermore,a cold resistance experiment was conducted at one of these sites to estimate the lethal temperature causing 50%frost damage(LT_(50))of 11 alpine species.The majority of variations in 12 leaf traits of alpine plants were captured by three trait axes,in which leaf carbon(LCC)and NSC(including leaf starch;LSC and leaf soluble sugars;LSS)were clustered in a new dimension(PC3)beyond leaf size and structure,and resource economics.Although LCC,LSC and LSS all showed negative correlations with mean annual temperature,a significant negative correlation was only found between LSS and LT_(50).It indicated that PC3 was able to reflect the cold-tolerance of alpine plants to some extent,in which LSS was the most critical trait.The storage and transformation of NSC under stressful conditions could reflect a dimension of long-term metabolic adaptation and cold-tolerance,which is an extension of the resource-utilization strategy beyond construction cost and growth.展开更多
基金National Natural Science Foundation of China(Grant No.30271093)
文摘The differences of glucose-6P dehydrogenase (G6PDH) activity and freezing resistance induced by freezing acclimation between cuttings of freezing-sensitive P. tomentosa and freezing-resistant P. suaveolens were compared for exploring the role of G6PDH on the enhancement of freezing resistance induced by freezing acclimation. After 5 d of freezing acclimation at -3 ℃, the LT50 of P. tomentosa has decreased from -6.2 ℃ in control cuttings to -14.3 ℃ in freezing acclimated ones, and the increase of G6PDH activity was observed in freezing acclimated cuttings as compared with control ones. Whereas, when P. suaveolens was freezing acclimated at -20℃ for 5 d, the LT50 has decreased from -27.1℃ in control cuttings to -43.5 ℃ in freezing acclimated ones, and the activity of G6PDH increased considerably. In addition, the increase of LT50 and the decrease of G6PDH activity resulting from 2 d of deacclimation at 25 ℃ were found in two kinds of freezing acclimated cuttings. It is concluded that the increase in the activity of G6PDH may associate with the inherited freezing resistance of species and the enhancement of freezing resistance of cuttings, and may play an important role in the antifreeze process under freezing temperature, which would provide the basis for the study on the molecular mechanism of freezing resistance in P. suaveolens and the cloning of gene associated with freezing resistance.
基金supported by the National Natural Science Foundation of China(32192461,32271619 and 32160285)the Natural Science Foundation of Science&Technology Department of Qinghai(2020-ZJ-952Q).
文摘Alpine plants possess unique traits to adapt alpine environments.Whether leaf trait relationships of alpine plants can be captured by the two trait dimensions of organ size and resource economics is unknown.We hypothesized that,beyond the trait dimensions of leaf size and resource economics,nonstructured carbohydrates(NSC)would reflect a dimension of cold-tolerance in alpine plants.To test this hypothesis,we measured 12 leaf traits critical to leaf construction and growth in 143 species across 7 sites ranging from alpine steppes to alpine meadows along an environmental gradient on the Tibetan Plateau.Furthermore,a cold resistance experiment was conducted at one of these sites to estimate the lethal temperature causing 50%frost damage(LT_(50))of 11 alpine species.The majority of variations in 12 leaf traits of alpine plants were captured by three trait axes,in which leaf carbon(LCC)and NSC(including leaf starch;LSC and leaf soluble sugars;LSS)were clustered in a new dimension(PC3)beyond leaf size and structure,and resource economics.Although LCC,LSC and LSS all showed negative correlations with mean annual temperature,a significant negative correlation was only found between LSS and LT_(50).It indicated that PC3 was able to reflect the cold-tolerance of alpine plants to some extent,in which LSS was the most critical trait.The storage and transformation of NSC under stressful conditions could reflect a dimension of long-term metabolic adaptation and cold-tolerance,which is an extension of the resource-utilization strategy beyond construction cost and growth.
