本文主要研究内容
作者朱珺（2019）在《NRT1.1在植物响应铅胁迫中的作用及机制》一文中研究指出：近年来随着工业化的发展,土壤铅(Pb)的污染问题也日渐凸显。土壤中的铅可通过食物链进入人体危害健康。因此,研发有效的技术或方法减控作物的铅积累迫在眉睫。探明植物养分与铅积累之间的关系,通过生物技术手段或遗传育种途径减控作物的铅积累被认为是一种经济、环保的策略。研究发现,植物的铅吸收可能与氮素营养密切相关,但是关于氮素吸收系统在植物响应铅胁迫中的作用及其生理与分子机制尚不清楚。为此,本文以拟南芥野生型和硝酸盐转运蛋白相关突变体为材料,运用植物生理学、分子生物学等手段,研究了 NRTs在植物应答Pb2+胁迫中的作用机制。主要研究结果如下:首先采用无损伤微电极离子流量检测系统,研究了Pb2+胁迫下野生型拟南芥根系净NO3-通量的变化。结果表明,Pb2+胁迫引起野生型拟南芥根系分生区、伸长区、成熟区三个部位净NO3-流入量显著上升。进一步研究显示,Pb2+胁迫显著促进了野生型拟南芥根系中硝酸盐转运蛋白NRT1.1基因的表达,其它硝酸盐转运蛋白NRT1.2、NRT2.1、NRT2.2和NRT2.4基因的表达量则无显著变化。转基因植物pNRT1.1::NRT1.1-GFP受到Pb2+胁迫后根部NRT1.1-GFP蛋白表达水平也显著上升,而NRT1.1功能缺失突变体nrt1.1-1和chl1.5在受到Pb2+胁迫后根系三个部位净NO3-通量并无显著差异。这些结果说明Pb2+胁迫能够通过促进植物NRT1.1的活性增强根系的NO3-吸收。采用琼脂平板培养的方法,进一步研究了Pb2+胁迫对拟南芥野生型Col-0和NRT1.1功能缺失突变体nrt1.1-1和chl1.5生长状况及铅积累水平的影响。结果显示,Pb2+胁迫对nrt1.1-1和chl1.5突变体植株根系伸长量的抑制显著大于Col-0,突变体地下部和地上部铅积累量显著高于Col-0,另一NRT1.1功能缺失突变体chl1.6生长状况和铅含量结果也与之相似。对Col-0、nrt1.1-1和chl1.5三种基因型植株膜脂过氧化损伤指标(MDA含量)的测定中发现,nrt1.1-1和chl1.5突变体植株质膜损伤相比于Col-0更严重。当NRT1.1功能得到回补的pNRT1.1::NRT1.1-GFP转基因植株受到Pb2+胁迫时,其表型和铅积累水平与Col-0一致,这些结果说明NRT1.1通过抑制植物Pb2+吸收调控植物铅耐性。此外,本论文也探究了Pb2+胁迫对于其他硝酸盐转运蛋白基因突变体nrt1.2、nrt2.1、nrt2.2和nrt2.4与其对应野生型Col-0或者Ler的影响,结果显示野生型和突变体之间并无显著性差异。这些结果说明NRT1.1参与的植物耐Pb2+胁迫响应是一个相对专一的过程。基于上述结果,进一步研究了 NRT1.1在调控植物耐铅中的作用机制。结果发现,nrtl.1-1和chll.5突变体在受到Pb2+胁迫后其平板培养基根际pH显著低于Col-0,基于GEO-CHEM系统,对不同pH条件下Pb2+活度的理论计算发现pH降低导致的Pb2+有效性提高很可能是nrtl.1-1和chl1.5突变体受到更严重Pb2+毒害的原因。为此,对MES缓冲pH条件下Col-0、nrt1.1-1和chl1.5三种基因型植株受到Pb2+胁迫后的生长状况及铅积累水平也进行了测定,发现pH缓冲条件使Pb2+对nrt1.1-1和chl1.5突变体的毒害得到显著缓解,其铅积累量和根际pH相比与Col-0的差异也显著减少。这些结果说明Pb2+胁迫下植物根系NRT1.1表达上调从而抑制根际pH降低是植物具有较强铅耐性的关键机制。另外,在不同硝铵比培养基对Col-0、nrt1.1-1和chW1.5三种基因型植株受Pb2+胁迫的影响研究中发现,只有NO3-和NH4+共同供应条件下,NRT1.1调控的植物耐Pb2+胁迫才起作用。为探明NO3-在植物耐Pb2+胁迫时所起的作用,我们也研究了 Pb2+胁迫对NO3-吸收功能缺失突变体chl1.9和NO3-感应功能缺失突变体nlp7-2生长状况及铅积累量的影响,结果表明NO3-吸收过程而非信号过程参与了植物耐Pb2+胁迫的响应。综合以上结果,我们认为NRT1.1在植物耐Pb2+胁迫中的作用机制为:NO3-和NH4+共存条件下,Pb2+胁迫促进NRT1.1介导的N03-吸收,NO3-吸收消耗H+引起植物根际pH上升,从而降低根际Pb2+有效性,减少植物对铅的吸收。
Abstract
jin nian lai sui zhao gong ye hua de fa zhan ,tu rang qian (Pb)de wu ran wen ti ye ri jian tu xian 。tu rang zhong de qian ke tong guo shi wu lian jin ru ren ti wei hai jian kang 。yin ci ,yan fa you xiao de ji shu huo fang fa jian kong zuo wu de qian ji lei pai zai mei jie 。tan ming zhi wu yang fen yu qian ji lei zhi jian de guan ji ,tong guo sheng wu ji shu shou duan huo wei chuan yo chong tu jing jian kong zuo wu de qian ji lei bei ren wei shi yi chong jing ji 、huan bao de ce lve 。yan jiu fa xian ,zhi wu de qian xi shou ke neng yu dan su ying yang mi qie xiang guan ,dan shi guan yu dan su xi shou ji tong zai zhi wu xiang ying qian xie pai zhong de zuo yong ji ji sheng li yu fen zi ji zhi shang bu qing chu 。wei ci ,ben wen yi ni na gai ye sheng xing he xiao suan yan zhuai yun dan bai xiang guan tu bian ti wei cai liao ,yun yong zhi wu sheng li xue 、fen zi sheng wu xue deng shou duan ,yan jiu le NRTszai zhi wu ying da Pb2+xie pai zhong de zuo yong ji zhi 。zhu yao yan jiu jie guo ru xia :shou xian cai yong mo sun shang wei dian ji li zi liu liang jian ce ji tong ,yan jiu le Pb2+xie pai xia ye sheng xing ni na gai gen ji jing NO3-tong liang de bian hua 。jie guo biao ming ,Pb2+xie pai yin qi ye sheng xing ni na gai gen ji fen sheng ou 、shen chang ou 、cheng shou ou san ge bu wei jing NO3-liu ru liang xian zhe shang sheng 。jin yi bu yan jiu xian shi ,Pb2+xie pai xian zhe cu jin le ye sheng xing ni na gai gen ji zhong xiao suan yan zhuai yun dan bai NRT1.1ji yin de biao da ,ji ta xiao suan yan zhuai yun dan bai NRT1.2、NRT2.1、NRT2.2he NRT2.4ji yin de biao da liang ze mo xian zhe bian hua 。zhuai ji yin zhi wu pNRT1.1::NRT1.1-GFPshou dao Pb2+xie pai hou gen bu NRT1.1-GFPdan bai biao da shui ping ye xian zhe shang sheng ,er NRT1.1gong neng que shi tu bian ti nrt1.1-1he chl1.5zai shou dao Pb2+xie pai hou gen ji san ge bu wei jing NO3-tong liang bing mo xian zhe cha yi 。zhe xie jie guo shui ming Pb2+xie pai neng gou tong guo cu jin zhi wu NRT1.1de huo xing zeng jiang gen ji de NO3-xi shou 。cai yong qiong zhi ping ban pei yang de fang fa ,jin yi bu yan jiu le Pb2+xie pai dui ni na gai ye sheng xing Col-0he NRT1.1gong neng que shi tu bian ti nrt1.1-1he chl1.5sheng chang zhuang kuang ji qian ji lei shui ping de ying xiang 。jie guo xian shi ,Pb2+xie pai dui nrt1.1-1he chl1.5tu bian ti zhi zhu gen ji shen chang liang de yi zhi xian zhe da yu Col-0,tu bian ti de xia bu he de shang bu qian ji lei liang xian zhe gao yu Col-0,ling yi NRT1.1gong neng que shi tu bian ti chl1.6sheng chang zhuang kuang he qian han liang jie guo ye yu zhi xiang shi 。dui Col-0、nrt1.1-1he chl1.5san chong ji yin xing zhi zhu mo zhi guo yang hua sun shang zhi biao (MDAhan liang )de ce ding zhong fa xian ,nrt1.1-1he chl1.5tu bian ti zhi zhu zhi mo sun shang xiang bi yu Col-0geng yan chong 。dang NRT1.1gong neng de dao hui bu de pNRT1.1::NRT1.1-GFPzhuai ji yin zhi zhu shou dao Pb2+xie pai shi ,ji biao xing he qian ji lei shui ping yu Col-0yi zhi ,zhe xie jie guo shui ming NRT1.1tong guo yi zhi zhi wu Pb2+xi shou diao kong zhi wu qian nai xing 。ci wai ,ben lun wen ye tan jiu le Pb2+xie pai dui yu ji ta xiao suan yan zhuai yun dan bai ji yin tu bian ti nrt1.2、nrt2.1、nrt2.2he nrt2.4yu ji dui ying ye sheng xing Col-0huo zhe Lerde ying xiang ,jie guo xian shi ye sheng xing he tu bian ti zhi jian bing mo xian zhe xing cha yi 。zhe xie jie guo shui ming NRT1.1can yu de zhi wu nai Pb2+xie pai xiang ying shi yi ge xiang dui zhuan yi de guo cheng 。ji yu shang shu jie guo ,jin yi bu yan jiu le NRT1.1zai diao kong zhi wu nai qian zhong de zuo yong ji zhi 。jie guo fa xian ,nrtl.1-1he chll.5tu bian ti zai shou dao Pb2+xie pai hou ji ping ban pei yang ji gen ji pHxian zhe di yu Col-0,ji yu GEO-CHEMji tong ,dui bu tong pHtiao jian xia Pb2+huo du de li lun ji suan fa xian pHjiang di dao zhi de Pb2+you xiao xing di gao hen ke neng shi nrtl.1-1he chl1.5tu bian ti shou dao geng yan chong Pb2+du hai de yuan yin 。wei ci ,dui MEShuan chong pHtiao jian xia Col-0、nrt1.1-1he chl1.5san chong ji yin xing zhi zhu shou dao Pb2+xie pai hou de sheng chang zhuang kuang ji qian ji lei shui ping ye jin hang le ce ding ,fa xian pHhuan chong tiao jian shi Pb2+dui nrt1.1-1he chl1.5tu bian ti de du hai de dao xian zhe huan jie ,ji qian ji lei liang he gen ji pHxiang bi yu Col-0de cha yi ye xian zhe jian shao 。zhe xie jie guo shui ming Pb2+xie pai xia zhi wu gen ji NRT1.1biao da shang diao cong er yi zhi gen ji pHjiang di shi zhi wu ju you jiao jiang qian nai xing de guan jian ji zhi 。ling wai ,zai bu tong xiao an bi pei yang ji dui Col-0、nrt1.1-1he chW1.5san chong ji yin xing zhi zhu shou Pb2+xie pai de ying xiang yan jiu zhong fa xian ,zhi you NO3-he NH4+gong tong gong ying tiao jian xia ,NRT1.1diao kong de zhi wu nai Pb2+xie pai cai qi zuo yong 。wei tan ming NO3-zai zhi wu nai Pb2+xie pai shi suo qi de zuo yong ,wo men ye yan jiu le Pb2+xie pai dui NO3-xi shou gong neng que shi tu bian ti chl1.9he NO3-gan ying gong neng que shi tu bian ti nlp7-2sheng chang zhuang kuang ji qian ji lei liang de ying xiang ,jie guo biao ming NO3-xi shou guo cheng er fei xin hao guo cheng can yu le zhi wu nai Pb2+xie pai de xiang ying 。zeng ge yi shang jie guo ,wo men ren wei NRT1.1zai zhi wu nai Pb2+xie pai zhong de zuo yong ji zhi wei :NO3-he NH4+gong cun tiao jian xia ,Pb2+xie pai cu jin NRT1.1jie dao de N03-xi shou ,NO3-xi shou xiao hao H+yin qi zhi wu gen ji pHshang sheng ,cong er jiang di gen ji Pb2+you xiao xing ,jian shao zhi wu dui qian de xi shou 。
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论文作者分别是来自浙江大学的朱珺，发表于刊物浙江大学2019-04-17论文，是一篇关于铅胁迫论文,拟南芥论文,铅耐性论文,浙江大学2019-04-17论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自浙江大学2019-04-17论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：铅胁迫论文; 拟南芥论文; 铅耐性论文; 浙江大学2019-04-17论文;