The selection of drought-tolerant plants is an important aspect of plant breeding.We studied physiological and biochemical mechanisms of different ploidies of Populus ussuriensis Kom.that relate to drought stress tole...The selection of drought-tolerant plants is an important aspect of plant breeding.We studied physiological and biochemical mechanisms of different ploidies of Populus ussuriensis Kom.that relate to drought stress tolerance.We used a 5%(v/v)polyethylene glycol(PEG-6000)solution to simulate drought stress.We recorded leaf phenotypes including color,dry area and curl degree.We evaluated sequential variations in some drought stress tolerance-related physiological and biochemical indices and compared these among diploid clones(CK),triploid clones(T12)and tetraploid clones(F20).T12 leaves exhibited slightly more drought stress damage than CK and F20 leaves.CK leaves suffered the most severe drought stress damage.The physiological and biochemical indices of the different ploidies differed significantly 12 days after drought stress treatment.The activities of superoxide dismutase,peroxidase,catalase and proline in the triploid(T12)leaves were the highest.The relative electric conductivity and malondialdehyde content of T12 leaves were the lowest.The index values of F20 were between those ofthe diploid and triploid.In consideration of these results,the drought resistance of the three different ploidies of P.ussuriensis can be ranked as T12>F20>CK.We speculate that the gene expression patterns of polyploid clones of poplar will change after genome doubling and that some of the drought stress tolerance-related physiological and biochemical indices will be improved,resulting in greater drought tolerance of polyploid clones.展开更多
The genus Populus contains some of the most economically important tree species and hybrids in the world. We compared productivity of short and long-rotation poplar plantations using published data from 23 countries t...The genus Populus contains some of the most economically important tree species and hybrids in the world. We compared productivity of short and long-rotation poplar plantations using published data from 23 countries to determine if climate, particularly temperature, had any effect on the observed patterns of productivity. We discovered that climate factors (related to temperature) and clone origin (pure species or hybrids) slightly influenced productivity of long rotation forests more than short rotation plantations. While long rotation plantation productivity exhibited positive correlations with increasing temperature during winter and decreasing heat during summer, short rotation plantations showed weak positive relationship among productivity and increasing yearly temperature and the number of hot days. It was apparent that short rotation plantations productivity was less dependent on regional climatic variables or origin of clone. However, it appears that overall, regardless of the system, Populus species are generally adapted to a range of climatic conditions where they are planted.展开更多
It is of great importance to better understand how trees regulate nitrogen(N) uptake under N deficiency conditions which severely challenge afforestation practices, yet the underlying molecular mechanisms have not bee...It is of great importance to better understand how trees regulate nitrogen(N) uptake under N deficiency conditions which severely challenge afforestation practices, yet the underlying molecular mechanisms have not been well elucidated. Here,we functionally characterized PuHox52, a Populus ussuriensis HD-ZIP transcription factor, whose overexpression greatly enhanced nutrient uptake and plant growth under N deficiency. We first conducted an RNA sequencing experiment to obtain root transcriptome using PuHox52-overexpression lines of P. ussuriensis under low N treatment. We then performed multiple genetic and phenotypic analyses to identify key target genes of PuHox52 and validated how they acted against N deficiency under PuHox52 regulation.PuHox52 was specifically induced in roots by N deficiency, and overexpression of PuHox52promoted N uptake, plant growth, and root development. We demonstrated that several nitrate-responsive genes(PuNRT1.1, PuNRT2.4,PuCLC-b, PuNIA2, PuNIR1, and PuNLP1),phosphate-responsive genes(PuPHL1A and PuPHL1B), and an iron transporter gene(PuIRT1) were substantiated to be direct targets of PuHox52. Among them, PuNRT1.1, PuPHL1A/B, and PuIRT1 were upregulated to relatively higher levels during PuHox52-mediated responses against N deficiency in PuHox52-overexpression lines compared to WT. Our study revealed a novel regulatory mechanism underlying root adaption to N deficiency where PuHox52 modulated a coordinated uptake of nitrate, phosphate, and iron through 'PuHox52-PuNRT1.1', 'PuHox52-PuPHL1A/PuPHL1B', and'PuHox52-PuIRT1' regulatory relationships in poplar roots.展开更多
Dry seeds of Populus ussuriensis collected from Heilongjiang area were carried by the recoverable satellite for mutagenesis.Then the growth traits and antioxidant enzymes activities of seedlings from the spaceflight-t...Dry seeds of Populus ussuriensis collected from Heilongjiang area were carried by the recoverable satellite for mutagenesis.Then the growth traits and antioxidant enzymes activities of seedlings from the spaceflight-treated seeds and controls were analyzed.The results showed that the growth traits of the seedlings after spaceflight varied to some degree,but most of the variation was not remarkable.There were no significant changes in soluble protein content,malondialdehyde(MDA)content and superoxide dismutase(SOD)activity in seedlings with response to spaceflight treatment.However,activities of ascorbate peroxidase(APX)and guaiacol peroxidase(POD)in the poplar seedlings after spaceflight were significantly higher than those from the ground control.It suggested that space condition altered the poplar traits in some degree,and the higher antioxidant enzymes might failitate themselves to avoid some damage from active oxygen.展开更多
基金supported by the National Key R&D Program of China(Grant No.2016YFD0600404)
文摘The selection of drought-tolerant plants is an important aspect of plant breeding.We studied physiological and biochemical mechanisms of different ploidies of Populus ussuriensis Kom.that relate to drought stress tolerance.We used a 5%(v/v)polyethylene glycol(PEG-6000)solution to simulate drought stress.We recorded leaf phenotypes including color,dry area and curl degree.We evaluated sequential variations in some drought stress tolerance-related physiological and biochemical indices and compared these among diploid clones(CK),triploid clones(T12)and tetraploid clones(F20).T12 leaves exhibited slightly more drought stress damage than CK and F20 leaves.CK leaves suffered the most severe drought stress damage.The physiological and biochemical indices of the different ploidies differed significantly 12 days after drought stress treatment.The activities of superoxide dismutase,peroxidase,catalase and proline in the triploid(T12)leaves were the highest.The relative electric conductivity and malondialdehyde content of T12 leaves were the lowest.The index values of F20 were between those ofthe diploid and triploid.In consideration of these results,the drought resistance of the three different ploidies of P.ussuriensis can be ranked as T12>F20>CK.We speculate that the gene expression patterns of polyploid clones of poplar will change after genome doubling and that some of the drought stress tolerance-related physiological and biochemical indices will be improved,resulting in greater drought tolerance of polyploid clones.
文摘The genus Populus contains some of the most economically important tree species and hybrids in the world. We compared productivity of short and long-rotation poplar plantations using published data from 23 countries to determine if climate, particularly temperature, had any effect on the observed patterns of productivity. We discovered that climate factors (related to temperature) and clone origin (pure species or hybrids) slightly influenced productivity of long rotation forests more than short rotation plantations. While long rotation plantation productivity exhibited positive correlations with increasing temperature during winter and decreasing heat during summer, short rotation plantations showed weak positive relationship among productivity and increasing yearly temperature and the number of hot days. It was apparent that short rotation plantations productivity was less dependent on regional climatic variables or origin of clone. However, it appears that overall, regardless of the system, Populus species are generally adapted to a range of climatic conditions where they are planted.
基金supported by the NSFC (31971671)the Fundamental Research Funds for the Central Universities of China (2572018CL04)+1 种基金the China Postdoctoral Science Foundation (2021M700733)the Heilongjiang Touyan Innovation Team Program (Tree Genetics and Breeding Innovation Team)。
文摘It is of great importance to better understand how trees regulate nitrogen(N) uptake under N deficiency conditions which severely challenge afforestation practices, yet the underlying molecular mechanisms have not been well elucidated. Here,we functionally characterized PuHox52, a Populus ussuriensis HD-ZIP transcription factor, whose overexpression greatly enhanced nutrient uptake and plant growth under N deficiency. We first conducted an RNA sequencing experiment to obtain root transcriptome using PuHox52-overexpression lines of P. ussuriensis under low N treatment. We then performed multiple genetic and phenotypic analyses to identify key target genes of PuHox52 and validated how they acted against N deficiency under PuHox52 regulation.PuHox52 was specifically induced in roots by N deficiency, and overexpression of PuHox52promoted N uptake, plant growth, and root development. We demonstrated that several nitrate-responsive genes(PuNRT1.1, PuNRT2.4,PuCLC-b, PuNIA2, PuNIR1, and PuNLP1),phosphate-responsive genes(PuPHL1A and PuPHL1B), and an iron transporter gene(PuIRT1) were substantiated to be direct targets of PuHox52. Among them, PuNRT1.1, PuPHL1A/B, and PuIRT1 were upregulated to relatively higher levels during PuHox52-mediated responses against N deficiency in PuHox52-overexpression lines compared to WT. Our study revealed a novel regulatory mechanism underlying root adaption to N deficiency where PuHox52 modulated a coordinated uptake of nitrate, phosphate, and iron through 'PuHox52-PuNRT1.1', 'PuHox52-PuPHL1A/PuPHL1B', and'PuHox52-PuIRT1' regulatory relationships in poplar roots.
文摘Dry seeds of Populus ussuriensis collected from Heilongjiang area were carried by the recoverable satellite for mutagenesis.Then the growth traits and antioxidant enzymes activities of seedlings from the spaceflight-treated seeds and controls were analyzed.The results showed that the growth traits of the seedlings after spaceflight varied to some degree,but most of the variation was not remarkable.There were no significant changes in soluble protein content,malondialdehyde(MDA)content and superoxide dismutase(SOD)activity in seedlings with response to spaceflight treatment.However,activities of ascorbate peroxidase(APX)and guaiacol peroxidase(POD)in the poplar seedlings after spaceflight were significantly higher than those from the ground control.It suggested that space condition altered the poplar traits in some degree,and the higher antioxidant enzymes might failitate themselves to avoid some damage from active oxygen.
