Differences in carbon and nitrogen metabolism between male and female Populus cathayana in response to deficient nitrogen
Differences in carbon and nitrogen metabolism between male and female Populus cathayana in response to deficient nitrogen
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缺氮时雄性和雌性青杨碳氮代谢的差异
DOI：
10.1093/treephys/tpaa108
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发表时间：
2021
期刊：
影响因子：
4
通讯作者：
Guo Qingxue
中科院分区：
文献类型：
--
作者：
Wu Xiaoyi;Liu Jiantong;Meng Qiqi;Fang Shiyan;Kang Jieyu;Guo Qingxue
在碳和氮的代谢过程中，对氮的供应作出反应，发生两性异形。在严重落叶条件下，两性间碳的固定和再活化以及氮的分配和同化的差异可能不同。以雌雄异株的青杨为试材，研究了两种氮素水平下的两次去叶处理。在缺氮条件下，长期严重落叶后，雄株叶片的气体交换和荧光特性增强，因而具有较高的固碳能力。雄株叶片脱落酸、气孔导度和叶片蔗糖磷酸合成酶活性较高，增加了蔗糖向汇的运输。在氮素缺乏条件下，对照组雄性根系淀粉积累量分别比雄性高131.10%和90.65%，而雌性根系淀粉积累量分别比雌性高40.55%和52.81%。雄株分配给叶片的非蛋白氮（NNon-p）较少，但具有较高的氮利用效率（光合氮利用效率）、较高的谷氨酸脱氢酶（GDH）和较高的叶片GDH表达。雌株叶片中茉莉酸含量和NNon-p含量均高于雄株，说明在缺氮条件下，长期严重落叶后，雌株比雄株分配更多的碳和氮用于防御化学物质。
Sexual dimorphism occurs regarding carbon and nitrogen metabolic processes in response to nitrogen supply. Differences in fixation and remobilization of carbon and allocation and assimilation of nitrogen between sexes may differ under severe defoliation. The dioecious speciesPopulus cathayanawas studied after two defoliation treatments with two N levels. Males had a higher capacity of carbon fixation because of higher gas exchange and fluorescence traits of leaves after severe long-term defoliation under deficient N. Males had higher leaf abscisic acid, stomatal conductance and leaf sucrose phosphate synthase activity increasing transport of sucrose to sinks. Males had a higher carbon sink than females, because under N-deficient conditions, males accumulated >131.10% and 90.65% root starch than males in the control, whereas females accumulated >40.55% and 52.81%, respectively, than females in the control group. Males allocated less non-protein N (NNon-p) to leaves, having higher nitrogen use efficiency (photosynthetic nitrogen use efficiency), higher glutamate dehydrogenase (GDH) and higher leafGDHexpression, even after long-term severe defoliation under deficient N. Females had higher leaf jasmonic acid concentration and NNon-p. The present study suggested that females allocated more carbon and nitrogen to defense chemicals than males after long-term severe defoliation under deficient N.