The heavy metal ATPase(HMA)subfamily is mainly involved in heavy metal(HM)tolerance and transport in plants,but an understanding of the definite roles and mechanisms of most HMA members are still limited.In the presen...The heavy metal ATPase(HMA)subfamily is mainly involved in heavy metal(HM)tolerance and transport in plants,but an understanding of the definite roles and mechanisms of most HMA members are still limited.In the present study,we identified 14 candidate HMA genes named BrrHMAl—BrrHMA8 from the turnip genome and analyzed the phylogeny,gene structure,chromosome distribution,and conserved domains and motifs of HMAs in turnip(Brassica rapa var.rapa).According to our phylogenetic tree,the BrrHMAs are divided into a Zn/Cd/Co/Pb subclass and Cu/Ag subclass.The BrrHMA members show similar structural characteristics within subclasses.To explore the roles of BrrHMAs in turnip,we compared the gene sequences and expression patterns of the BrrHMA genes between a Cd-tolerant landrace and a Cd-sensitive landrace.Most BrrHMA genes showed similar spatial expression patterns in both Cd-tolerant and Cd-sensitive turnip landraces;some BrrHMA genes,however,were differentially expressed in specific tissue in Cd-tolerant and Cd-sensitive turnip.Specifically,BrrHMA genes in the Zn/Cd/Co/Pb subclass shared the same coding sequence but were differentially expressed in Cd-tolerant and Cd-sensitive turnip landraces under Cd stress.Our findings suggest that the stable expression and up-regulated expression of BrrHMA Zn/Cd/Co/Pb subclass genes under Cd stress may contribute to the higher Cd tolerance of turnip landraces.展开更多
为了对比研究低温处理前后煤体孔隙结构的变化规律,选择内蒙古赤峰市平庄褐煤为试验对象,利用可程式恒温恒湿试验箱对煤体进行低温-20℃处理,运用全自动比表面积及孔径分析仪对低温处理前后的煤体进行氮气吸附实验,通过BET、BJH、DFT模...为了对比研究低温处理前后煤体孔隙结构的变化规律,选择内蒙古赤峰市平庄褐煤为试验对象,利用可程式恒温恒湿试验箱对煤体进行低温-20℃处理,运用全自动比表面积及孔径分析仪对低温处理前后的煤体进行氮气吸附实验,通过BET、BJH、DFT模型计算分析煤体的比表面积、孔体积及孔径分布等孔隙结构参数,并通过扫描电子显微镜(scanning electron microscope,SEM)对煤样处理前后的微观形貌特征进行观察与分析。结果表明:低温处理后煤体的比表面积和孔体积分别增大了31.34%和24.06%;微孔和介孔数量增加十分明显,煤体的吸附性能得到提高。低温处理不仅使煤体生成了新的微孔,而且使原本的孔隙向更大尺寸孔隙转化。煤体原本在2~5 nm和35~75 nm孔径范围内不存在孔隙,经过低温处理后,煤体在这2个孔径范围内生成了孔隙,进一步改善了煤体孔隙的多样性。展开更多
基金financially supported by the Western Youth Project B of the “Light of West China” Program of Chinese Academy of Sciences (Y7260411W1)the National Natural Science Foundation of China (31590823)
文摘The heavy metal ATPase(HMA)subfamily is mainly involved in heavy metal(HM)tolerance and transport in plants,but an understanding of the definite roles and mechanisms of most HMA members are still limited.In the present study,we identified 14 candidate HMA genes named BrrHMAl—BrrHMA8 from the turnip genome and analyzed the phylogeny,gene structure,chromosome distribution,and conserved domains and motifs of HMAs in turnip(Brassica rapa var.rapa).According to our phylogenetic tree,the BrrHMAs are divided into a Zn/Cd/Co/Pb subclass and Cu/Ag subclass.The BrrHMA members show similar structural characteristics within subclasses.To explore the roles of BrrHMAs in turnip,we compared the gene sequences and expression patterns of the BrrHMA genes between a Cd-tolerant landrace and a Cd-sensitive landrace.Most BrrHMA genes showed similar spatial expression patterns in both Cd-tolerant and Cd-sensitive turnip landraces;some BrrHMA genes,however,were differentially expressed in specific tissue in Cd-tolerant and Cd-sensitive turnip.Specifically,BrrHMA genes in the Zn/Cd/Co/Pb subclass shared the same coding sequence but were differentially expressed in Cd-tolerant and Cd-sensitive turnip landraces under Cd stress.Our findings suggest that the stable expression and up-regulated expression of BrrHMA Zn/Cd/Co/Pb subclass genes under Cd stress may contribute to the higher Cd tolerance of turnip landraces.
文摘为了对比研究低温处理前后煤体孔隙结构的变化规律,选择内蒙古赤峰市平庄褐煤为试验对象,利用可程式恒温恒湿试验箱对煤体进行低温-20℃处理,运用全自动比表面积及孔径分析仪对低温处理前后的煤体进行氮气吸附实验,通过BET、BJH、DFT模型计算分析煤体的比表面积、孔体积及孔径分布等孔隙结构参数,并通过扫描电子显微镜(scanning electron microscope,SEM)对煤样处理前后的微观形貌特征进行观察与分析。结果表明:低温处理后煤体的比表面积和孔体积分别增大了31.34%和24.06%;微孔和介孔数量增加十分明显,煤体的吸附性能得到提高。低温处理不仅使煤体生成了新的微孔,而且使原本的孔隙向更大尺寸孔隙转化。煤体原本在2~5 nm和35~75 nm孔径范围内不存在孔隙,经过低温处理后,煤体在这2个孔径范围内生成了孔隙,进一步改善了煤体孔隙的多样性。
