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杨树的氮营养在盐碱和镉胁迫下的作用
孙玉芳
Subtype博士
Thesis Advisor姚银安
2018-06-05
Degree Grantor中国科学院大学
Place of Conferral新疆乌鲁木齐
Degree Discipline理学博士
Keyword杨树 盐碱胁迫 氮营养 NRT 基因 镉胁迫 Poplars Salinity- alkali stress Nitrogen nutrition NRT genes Cadmium stress
Abstract胡杨(Populus euphratica Oliv.)属于杨柳科(Salicaceae)25-35 种落叶开花植物中的一种,原产于北半球的大部分地区。胡杨、新疆杨(Populus bolleana Lauche.)和俄罗斯杨(Populus Russkii Jabl.)在新疆地区普遍存在,且在长期的极端条件和自然选择下,这些树种演化出了许多抗逆境胁迫的功能基因。对这些基因的研究具有重要的意义。这三种杨树对盐和镉胁迫的抗性表现出极大的不同。胡杨有较强的抗盐胁迫的能力,新疆杨次之,而俄罗斯杨则对盐较敏感。我们研究了胡杨和新疆杨幼叶和老叶对碱胁迫的响应,发现碱胁迫下,胡杨具有较强的抗性,主要是因为一方面它通过有效的机制,将 Na+离子区隔化至液泡中从而避免离子伤害;另一方面碱胁迫下它能更灵活的调整氮的吸收和代谢。新疆杨对碱胁迫的主要适应策略是通过积累大量有毒离子至老叶中从而避免对幼叶的伤害。氮营养影响了新疆杨幼叶和老叶对盐胁迫的响应机制。盐胁迫下,新疆杨老叶中积累更多的 Na+,以此来保护幼叶免受盐胁迫的伤害。外部环境缺氮时,幼叶表现的更敏感,此时出现如老叶在盐胁迫下的损伤性状。缺氮时,老叶对幼叶的保护策略失去效用。氮营养对俄罗斯杨的盐胁迫抗性也有较大的影响。盐胁迫使俄罗斯杨的根和叶均受到较大的损伤。但是经过低氮的适应后,再加入温和的盐分胁迫,一定程度上可以缓解盐胁迫造成的伤害。俄罗斯杨具有较强的抗镉胁迫性,外界不同浓度的 NO3- 影响俄罗斯杨对镉胁迫的抗性。在一定的范围之内,随着外部环境 NO3- 浓度的升高,俄罗斯杨的抗镉胁迫性逐渐增强。然而,低浓度的 NO3-和过高浓度的 NO3-都降低了俄罗斯杨对镉胁迫的抗性。NRT 家族基因的表达受到各种胁迫因子的影响。我们从胡杨的基因组中,克隆了 NRT1;5A,NRT1;5C,NRT1;8A,NRT1;8B,NRT1;9B,NRT1;7,NRT3;1A,NRT3;1B,和 NRT3;2A 这几个基因,通过组织培养技术将这几个基因转入了烟草中,并获得了转基因烟草的 T2 代种子。逆境胁迫处理下发现,烟草 PeNRT1;5A,NRT1;5C,NRT1;8A,NRT1;8B,NRT1;9B 的转基因植株对镉胁迫有很强的抗性。另外,NRT1;8B,NRT1;9B 和 NRT1;5C 的异源表达烟草植株对铜胁迫也表现出较显著的抗性。
Other AbstractPopulus is a genus of 25–35 species of deciduous flowering plants in thefamily Salicaceae,native to most of the Northern Hemisphere. In China,Populusbolleana Lauche. (P. bolleana),Populus euphratica Oliv. (P. euphratica) andPopulus Russkii Jabl. (P. Russkii) are ubiquitous in Xinjiang. Under long-termextreme conditions and nature selection,those trees evolved functional genes that areresistant to adversity stress. The study of these genes is of great significance. Theresistance of the three poplars to salt and cadmium showed a great difference. P.euphratica has strong resistance to salt stress,followed by P. bolleana,while P.Russkii is more sensitive to salt. We studied the response of young and old leaves of P.euphratica and Populus bolleana to alkali stress. It found that under alkaline stress,P. euphratica has strong resistance. On the one hand,it compartmentalized Na+ionsinto vacuoles throµgh an effective mechanism to avoid ion damage; on the otherhand,it can adjust the absorption and metabolism of nitrogen more flexibly underalkaline stress. The main adaptation strategy of P. bolleana to alkali stress is toaccµMµLate a large nµMber of toxic ions into the old leaves so as to avoid damage toyoung leaves.Nitrogen nutrition affected the response mechanisms of young and old leaves of P.bolleana to salt stress. Under salt stress,more Na+ was accµMµLated in the old leavesof P. bolleana in order to protect young leaves from salt stress. In the absence ofnitrogen in the external environment,the young leaves are more sensitive to theappearance of damage,like the old leaves under the salt stress. In the absence ofnitrogen,the protection strategy of the old leaves on young leaves loses itseffectiveness.Nitrogen nutrition also has a great influence on the salt-stress resistance of P.Russkii. Salt stress leads to the roots and leaves of P. Russkii to be greatly damaged.However,after the adaptation to low nitrogen,adding mild salt stress can relieve thedamage caused by salt stress to a certain extent.P. Russkii has strong resistance to cadmium stress,and different concentrations of nitrate in the external environment affect the resistance of P. Russkii to cadmiumstress. Within a certain range,as the concentration of nitrate increased,the resistanceto cadmium stress of P. Russkii gradually increased. However,low and highconcentration of nitrate decreased the resistance of P. Russkii to cadmium stress.The expression of NRT family genes is affected by various stress factors. Wecloned NRT1;5A,NRT1;5C,NRT1;8A,NRT1;8B,NRT1;9B,NRT1;7,NRT3;1A,NRT3;1B,and NRT3;2A from the genome of P. euphratica. These genes weretransferred into tobacco by tissue culture techniques and T2 seeds of transgenictobacco were obtained. Through phenotype and physiology analysis,the transgenictobacco of NRT1;5A,NRT1;5C,NRT1;8A,NRT1;8B and NRT1;9B were highlyresistant to cadmium stress. In addition,heterologous expression of NRT1;8B,NRT1;9B and NRT1;5C in tobacco also showed significant resistance to copper stress.
Subject Area植物学
Language中文
Document Type学位论文
Identifierhttp://ir.xjlas.org/handle/365004/14937
Collection研究系统_荒漠环境研究室
Affiliation中国科学院新疆生态与地理研究所
First Author Affilication中国科学院新疆生态与地理研究所
Recommended Citation
GB/T 7714
孙玉芳. 杨树的氮营养在盐碱和镉胁迫下的作用[D]. 新疆乌鲁木齐. 中国科学院大学,2018.
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