Picea crassifolia and P.wilsonii,commonly used for afforestation in northern China,are increasingly likely to be subjected to high temperatures and soil drought stress as a result of global warming.However,little is k...Picea crassifolia and P.wilsonii,commonly used for afforestation in northern China,are increasingly likely to be subjected to high temperatures and soil drought stress as a result of global warming.However,little is known about the effects of these stresses on foliar photosynthesis in the two species.To investigate how photosynthetic characteristics and sensitivity respond to prolonged high temperatures and soil drought,foliar gas exchange and other closely related parameters were recorded from four-year-old seedlings of both species.Seedlings were grown under two temperature treatments(25/15 and 35/25 °C) and four soil water regimes [80,60,40 and 20% of maximum field capacity(FC)] for 4 months.Although all treatments significantly reduced photosynthetic rates(Pn) of both species,P.crassifolia exhibited greater photosynthetic acclimation than P.wilsonii.Differences in photosynthetic acclimation were mainly related to variations in stomatal conductance(Cond) and the maximum quantum yield of PSII(Fv/Fm) between treatments.Indeed,higher Cond and Fv/Fmin all treatments were shown for P.crassifolia than for P.wilsonii.Moreover,photosynthesis in P.crassifolia exhibited inherently lower temperature sensitivities(broader span for the temperature response curves; lower b) and higher thermostability(invariable b between treatments).Further,severe drought stress(20% FC) limited the survival of P.wilsonii.Our results indicate that P.wilsonii is more susceptible to high temperatures and soil drought stress.Planting P.crassifolia would be more expected to survive these conditions and hence be of greater benefit to forest stability if predicted increases in drought and temperature in northern China occur.展开更多
Expansins are cell-wall-loosening proteins that have multiple roles during plant development and stress- related processes. In this study, a novel expansin gene PwEXP2 was cloned by rapid amplification of cDNA ends ba...Expansins are cell-wall-loosening proteins that have multiple roles during plant development and stress- related processes. In this study, a novel expansin gene PwEXP2 was cloned by rapid amplification of cDNA ends based on the cDNA library of Picea wilsonii and EST fragment of PwEXP2. It was found that PwEXP2 coded 253 amino acids, and putative signal peptides exist at the N-terminal, followed by 8 cysteines, a HFD （His-Phe-Asp） conserved domain, and 4 tryptophan residues at the C-terminal. PwEXP2 was located in cytoplasm and nucleus when transformed in an onion epidermal cell. Quantitative real-time PCR assays showed that PwEXP2 was expressed in various tissues with a relatively high level in needles and low level in mature pollen. The expression level of PwEXP2 dramatically increased after seed germination. Gene expression profiles in abiotic stresses showed that PwEXP2 was induced by high temperature and osmotic stress but not involved in ABA-dependent signaling path- way. These results display the important roles of the PwEXP2 in plant development and multiple adversity stresses.展开更多
SWEET transporters play a pivotal role in sugar transport in plants.However,their functions in pollen tube growth,especially in coniferous species remain unknown.Here,we used RT-qPCR to reveal that a SWEET1 gene was s...SWEET transporters play a pivotal role in sugar transport in plants.However,their functions in pollen tube growth,especially in coniferous species remain unknown.Here,we used RT-qPCR to reveal that a SWEET1 gene was specifically expressed in pollen and pollen tubes of Picea wilsonii.A pollen germination assay showed that PwSWEET1 was induced by H3BO3 but not by Ca^2+.In a sugar specificity experiment,sucrose(Suc)and glucose(Glc)were effective sugars for pollen germination and pollen tube growth.PwSWEET1 expression was induced most by Suc and Glc.Heterologous expression of PwSWEET1 in yeast showed that PwSWEET1 can restore the glucose absorption in yeast strain EBY.VW4000,which has a hexose absorption defect,and the absorption of glucose is pH-independent.This evidence supports the involvment of PwSWEET1 in boron-dependent glucose transport in pollen germination and pollen tube growth of Picea wilsonii.展开更多
In this paper,the geographical distribution,community characteristics and DBH class structure of Picea neoveitchii Mast. population were investigated and analyzed by systematical and ecological approaches. In addition...In this paper,the geographical distribution,community characteristics and DBH class structure of Picea neoveitchii Mast. population were investigated and analyzed by systematical and ecological approaches. In addition,the endangered mechanism and the protection measures were put forward by analyzing the Picea neoveitchii Mast. resource distribution in Hubei Province to provide effective scientific basis for further research. The results showed that Picea neoveitchii Mast. was found in Baokang,Enshi,Shennongjia and Zhuxi of Hubei Province,there were 9 distribution points and only a wild forest was found in Baokang. The community of Baokang County was not rich in species composition and 32 species,29 genera and 21 families were examined. Meanwhile,temperate zone was the main flora element of this community,the phaenerophytes plant was most dominant and there were few hemicryptophytes and it lacked therophytes. In this community,Picea neoveitchii Mast. was in a dominant position,including lots of treelets,so the age structure of the population was growing.展开更多
This study represents a geographical approach to morphological variation of cones, needles and seeds in natural dragon spruce （Picea asperata Mast.） populations across western China and the relationship between morp...This study represents a geographical approach to morphological variation of cones, needles and seeds in natural dragon spruce （Picea asperata Mast.） populations across western China and the relationship between morphological traits and weather variation for the origins of populations. Significant differences were found for all cone, needle and seed traits among populations and trees within populations. The coefficients of variation in 2 higher latitude populations were higher than those in other populations in all traits except for needle width and seed width. Fairly high within-population variability was also detected for cone dry weight, seed dry weight and needle traits in this study. Cone length, cone width, cone dry weight, seed scale length, seed scale width and seed wing length were strongly positively intercorrelated. Seed length and seed dry weight showed a significantly positive correlation with seed wing length. And needle width showed a significant negative correlation with cone traits, seed scale length, seed wing length and seed length. The higher the annual mean temperature, the higher the average cone length. This study also revealed a negative linear dependence on latitude： the higher the latitude, the lower the population average seed length. Seed dry weight was positively and linearly related with altitude.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.31370603,31170571 and31522013)the Fundamental Research Funds for the Central Universities(lzujbky-2016-ct10)
文摘Picea crassifolia and P.wilsonii,commonly used for afforestation in northern China,are increasingly likely to be subjected to high temperatures and soil drought stress as a result of global warming.However,little is known about the effects of these stresses on foliar photosynthesis in the two species.To investigate how photosynthetic characteristics and sensitivity respond to prolonged high temperatures and soil drought,foliar gas exchange and other closely related parameters were recorded from four-year-old seedlings of both species.Seedlings were grown under two temperature treatments(25/15 and 35/25 °C) and four soil water regimes [80,60,40 and 20% of maximum field capacity(FC)] for 4 months.Although all treatments significantly reduced photosynthetic rates(Pn) of both species,P.crassifolia exhibited greater photosynthetic acclimation than P.wilsonii.Differences in photosynthetic acclimation were mainly related to variations in stomatal conductance(Cond) and the maximum quantum yield of PSII(Fv/Fm) between treatments.Indeed,higher Cond and Fv/Fmin all treatments were shown for P.crassifolia than for P.wilsonii.Moreover,photosynthesis in P.crassifolia exhibited inherently lower temperature sensitivities(broader span for the temperature response curves; lower b) and higher thermostability(invariable b between treatments).Further,severe drought stress(20% FC) limited the survival of P.wilsonii.Our results indicate that P.wilsonii is more susceptible to high temperatures and soil drought stress.Planting P.crassifolia would be more expected to survive these conditions and hence be of greater benefit to forest stability if predicted increases in drought and temperature in northern China occur.
基金supported by National Natural Science Foundation(Grant No.31270663)a grant from Agricultural Ministry of China(Grant No.2013ZX08009003-002-004)
文摘Expansins are cell-wall-loosening proteins that have multiple roles during plant development and stress- related processes. In this study, a novel expansin gene PwEXP2 was cloned by rapid amplification of cDNA ends based on the cDNA library of Picea wilsonii and EST fragment of PwEXP2. It was found that PwEXP2 coded 253 amino acids, and putative signal peptides exist at the N-terminal, followed by 8 cysteines, a HFD （His-Phe-Asp） conserved domain, and 4 tryptophan residues at the C-terminal. PwEXP2 was located in cytoplasm and nucleus when transformed in an onion epidermal cell. Quantitative real-time PCR assays showed that PwEXP2 was expressed in various tissues with a relatively high level in needles and low level in mature pollen. The expression level of PwEXP2 dramatically increased after seed germination. Gene expression profiles in abiotic stresses showed that PwEXP2 was induced by high temperature and osmotic stress but not involved in ABA-dependent signaling path- way. These results display the important roles of the PwEXP2 in plant development and multiple adversity stresses.
基金This work was supported by the grant from Agricultural Ministry of China(No.2016ZX08009-003-002).
文摘SWEET transporters play a pivotal role in sugar transport in plants.However,their functions in pollen tube growth,especially in coniferous species remain unknown.Here,we used RT-qPCR to reveal that a SWEET1 gene was specifically expressed in pollen and pollen tubes of Picea wilsonii.A pollen germination assay showed that PwSWEET1 was induced by H3BO3 but not by Ca^2+.In a sugar specificity experiment,sucrose(Suc)and glucose(Glc)were effective sugars for pollen germination and pollen tube growth.PwSWEET1 expression was induced most by Suc and Glc.Heterologous expression of PwSWEET1 in yeast showed that PwSWEET1 can restore the glucose absorption in yeast strain EBY.VW4000,which has a hexose absorption defect,and the absorption of glucose is pH-independent.This evidence supports the involvment of PwSWEET1 in boron-dependent glucose transport in pollen germination and pollen tube growth of Picea wilsonii.
基金Supported By the Second National Investigation of Key Wild Plant Resources-Special Investigation of Picea neoveitchii Mast.Resources in Hubei Province
文摘In this paper,the geographical distribution,community characteristics and DBH class structure of Picea neoveitchii Mast. population were investigated and analyzed by systematical and ecological approaches. In addition,the endangered mechanism and the protection measures were put forward by analyzing the Picea neoveitchii Mast. resource distribution in Hubei Province to provide effective scientific basis for further research. The results showed that Picea neoveitchii Mast. was found in Baokang,Enshi,Shennongjia and Zhuxi of Hubei Province,there were 9 distribution points and only a wild forest was found in Baokang. The community of Baokang County was not rich in species composition and 32 species,29 genera and 21 families were examined. Meanwhile,temperate zone was the main flora element of this community,the phaenerophytes plant was most dominant and there were few hemicryptophytes and it lacked therophytes. In this community,Picea neoveitchii Mast. was in a dominant position,including lots of treelets,so the age structure of the population was growing.
文摘This study represents a geographical approach to morphological variation of cones, needles and seeds in natural dragon spruce （Picea asperata Mast.） populations across western China and the relationship between morphological traits and weather variation for the origins of populations. Significant differences were found for all cone, needle and seed traits among populations and trees within populations. The coefficients of variation in 2 higher latitude populations were higher than those in other populations in all traits except for needle width and seed width. Fairly high within-population variability was also detected for cone dry weight, seed dry weight and needle traits in this study. Cone length, cone width, cone dry weight, seed scale length, seed scale width and seed wing length were strongly positively intercorrelated. Seed length and seed dry weight showed a significantly positive correlation with seed wing length. And needle width showed a significant negative correlation with cone traits, seed scale length, seed wing length and seed length. The higher the annual mean temperature, the higher the average cone length. This study also revealed a negative linear dependence on latitude： the higher the latitude, the lower the population average seed length. Seed dry weight was positively and linearly related with altitude.
