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1.
叶酸又称为维生素B9,是生物体生长发育的重要辅因子。前期研究发现拟南芥叶酸代谢突变体的氮代谢也出现异常,但目前叶酸代谢影响植物氮代谢的分子机制还不是很清晰。以水稻日本晴为材料,分析不同氮浓度条件下施加5 甲酰四氢叶酸对水稻幼苗生长发育、氮代谢的影响及分子机制。结果表明:在低氮条件下,水稻幼苗的叶片发育缓慢,叶绿素含量、株高、鲜重均显著降低;在水稻幼苗根部施加5 甲酰四氢叶酸(200 μmol·L-1)能够显著促进幼苗在低氮条件下的生长发育,株高、鲜重、叶绿素含量均有提高,叶酸衍生物含量、可溶性蛋白含量、游离氨基酸含量均显著提高; 5 甲酰四氢叶酸处理后,幼苗体内的谷氨酸合酶活性增加、谷氨酸合酶基因的转录水平上调,推测叶酸可能通过促进水稻谷氨酸合酶基因表达、酶活性进而影响氮代谢。这些结果为理解叶酸代谢与植物氮代谢的作用关系奠定基础,为农业生产中缓解低氮胁迫、提高植物氮素利用效率提供新思路。  相似文献   

2.
水稻氮代谢决定了氮素的吸收、转运和同化,最终影响产量形成.外施水杨酸(SA)对植物氮代谢和氮肥利用效率发挥积极作用,但对其作用方式及SA与氮代谢之间的关系知之甚少,尤其缺乏分子水平的解析.本文从氮素的吸收形式、生理生化代谢及内源SA含量变化等方面对水稻氮素吸收利用的研究进行了综述,旨在从氮代谢角度阐释植株对氮素的运移特性、SA的调节效应及可能的作用方式,为发展节肥增效栽培和环境友好型稻作提供新思路.  相似文献   

3.
重金属胁迫和内生菌对植物氮代谢影响的研究进展   总被引:1,自引:0,他引:1  
由于近年来人类活动和工业化进程的逐步加快,人们面临重金属污染已经到了严峻的时刻。内生菌与植物共生能够提高宿主植物的生长发育、影响生理代谢水平。本文主要对国内外学者们对内生菌和重金属胁迫对植物影响以及结合近些年来逐步成为热点的植物氮代谢的相关研究进行了综述。  相似文献   

4.
为了了解内生菌对茅苍术道地性的影响,本文综述了各种内生菌引发的植物信号变化的异同,以及茅苍术内生菌在促进茅苍术生长以及多萜合成中的作用。内生菌可能被植物细胞表面受体所识别,通过活性氧、钙离子、一氧化氮3种第二信使以及多种植物激素信号引发植物代谢变化,进而累积次生代谢产物。受到影响的植物信号包括水杨酸、茉莉酸、脱落酸和乙烯。研究发现,内生菌的接种可能引起多种植物信号传递的变化,并且产生挥发油含量差异。  相似文献   

5.
硝态氮(NO3--N)和铵态氮(NH4+-N)是植物吸收的两种主要氮素形态.由于植物对NO3-和NH4+吸收和同化的机制不同,导致叶片及果实中有机酸含量差异很大.本文阐述了不同形态氮素对植物叶片内有机酸合成的影响,指出供NO3-植物叶片中苹果酸、α-酮戊二酸及柠檬酸含量均显著高于供NH4+植物.番茄果实中苹果酸和柠檬酸是两种含量最多的有机酸,也是影响果实品质的重要因素;进一步分析了番茄果实发育过程中有机酸种类、含量及相关有机酸代谢酶活性的变化,探讨了不同形态氮素对番茄果实中苹果酸和柠檬酸含量以及氮代谢和有机酸代谢关键酶活性的影响.提出氮素形态可能对果实中有机酸含量有重要的调控作用,以期为农业生产中采用不同形态氮素调控果实有机酸代谢提供理论依据.  相似文献   

6.
碳、氮代谢是植物体内最重要的两大代谢,对作物生物量积累与品质形成具有重要作用。在生产中,多依赖增加施肥量来提高作物产量,导致环境污染与不可持续发展,因此迫切需要选育高氮素利用效率的作物品种。植物氮素利用效率的提高,不仅依靠提高植物对氮肥的吸收能力,还需要考虑协调碳、氮代谢之间的关系。作为协调靶基因整个应答网络表达的主要调节因子,转录因子能影响整个应答网络中所涉及的代谢物变化。DNA结合单锌指蛋白(DNA binding with one finger, Dof)转录因子是植物中特有的转录因子,参与调控植物组织分化、种子萌发、物质代谢等生理生化过程。重点综述Dof转录因子在植物碳、氮代谢中的调控作用,在植物碳代谢中,Dof转录因子主要参与光合作用途径中关键基因和光合代谢产物的调控;在氮代谢中,Dof转录因子主要通过调控氮的吸收、转运和同化途径的关键基因促进氮同化,并通过协调碳氮代谢的平衡提高植物对氮素的利用效率,改善植物的品质和产量,这给利用Dof转录因子协调植物碳氮代谢关系、提高氮素利用效率和农艺性状的深入研究奠定了基础。  相似文献   

7.
为探究甘蓝型油菜硼氮交互作用的增产效应及其生理机制,通过水培试验和大田小区试验相结合的手段,分析了硼氮交互效应对油菜生长、氮素吸收利用、氮代谢酶活性以及籽粒产量的影响.结果表明:在苗期,硼缺乏显著抑制了不同氮供应水平下油菜根系生长发育;与低氮或低硼处理相比,硼氮平衡供给显著提高了氮素吸收及其相关基因的表达水平,改善了氮...  相似文献   

8.
植物氮素吸收过程研究进展   总被引:2,自引:0,他引:2  
氮是植株生长发育所需求的第一大矿质营养元素,主要通过根系从土壤吸收获得。因此,了解植物吸收氮素的过程及影响因素对明确氮素吸收机理,提高氮素吸收利用,促进植物生长具有重要意义。土壤中的氮素主要以无机态氮(NO-3、NH+4)和小分子有机态氮的形式存在,其中植物所能吸收利用的主要是NO-3态氮素。该研究介绍了植物对氮素的需求、NO-3吸收过程及其影响因素的研究进展。这对认识氮素吸收机理、提高氮素吸收效率具有重要的意义。  相似文献   

9.
郜玉钢  莫琪琪  赵岩  臧埔 《南方农业学报》2019,50(10):2234-2240
植物次生代谢产物是植物长期与生态环境适应的结果,具有多种药理、生理和生态学功能,已广泛应用于医药、保健品、化妆品、食品和农药等行业.文章重点介绍了病原菌、诱导子和内生菌介导植物次生代谢产物累积的概况,指出利用病原菌介导植物次生代谢累积作用不持久和不安全,诱导子介导虽安全但更不持久,内生菌介导远比生物侵害因子更安全、更可控和更持久,且经济可靠效率高,应用前景更理想;同时总结了内生菌介导植物次生代谢产物累积的主要途径,归纳了内生菌与宿主植物次生代谢的互作机制,并指出内生菌在药用植物药效成分累积中的作用机制.今后应借助高通量测序、SSH、HPLC、TLC、IR、MS和NMR等手段确定内生菌介导药用植物次生代谢产物累积的途径、种类及其差异基因,再结合药用植物次生代谢单体和差异基因表达量相关分析、Unigene注释、差异基因结构分析筛选候选基因并验证其功能,综合Unigene蛋白互作网络等分析和关键酶基因作用信号通路,确定内生菌介导药用植物次生代谢累积的分子机制.  相似文献   

10.
植物氮素吸收、运转和分配调控机制研究   总被引:3,自引:0,他引:3  
氮是影响植物生长发育的必需大量营养元素之一,是叶绿素、氨基酸、核酸、次生代谢产物的重要组分。目前在农业生产中氮肥施用过量、效率低下、对环境造成不利影响的问题非常严重。NH_4~+-N和NO_3~--N是植物吸收利用的主要无机氮素形态,植物在演替过程中逐渐形成高效吸收和利用氮素的生理和分子机制。本文重点综述了植物根系从土壤中吸收NH_4~+-N和NO_3~--N,再通过木质部和韧皮部转运至地上部并在各器官进行分配、利用的生理过程和分子调控机制研究进展,并对今后的氮素吸收、运转和分配的研究重点提出展望,这为生产上促进植物氮素吸收和利用,提高氮效率和增强农业生产力提供了理论基础。  相似文献   

11.
Nitrate reductase (NR) is a key enzyme for nitrogen assimilation in plants, and its activity is regulated by posttranslational phosphorylation. To investigate the effects of dephosphorylation of the NIA1 protein on the growth and the physiological and biochemical characteristics of rice under different forms of nitrogen supplies, the phenotypes, nitrogen metabolism and reactive oxygen metabolism were measured in NIA1 phosphorylation site-directed mutant lines (S532D and S532A), an OsNia1 over-expression line (OE) and Kitaake (wild type, WT). Compared with WT and OE, S532D and S532A have stronger nitrogen assimilation capacities. When ammonium nitrate served as the nitrogen source, the plant heights, dry weights of shoots and chlorophyll (Chl) contents of S532D and S532A were lower than those of the WT and OE, whereas hydrogen peroxide (H2O2), malondialdehyde (MDA) and nitrite contents were higher. When potassium nitrate served as the nitrogen source, the plant heights, dry weights of shoots and Chl contents of S532D and S532A were higher than those of the WT and OE, there were no significant differences in the contents of H2O2 and MDA in the leaves of the test materials, and the difference in nitrite contents among different lines decreased. When ammonium sulfate served as the nitrogen source, there were no significant differences in the physiological indexes of the test materials, except NR activity. Compared with ammonium nitrate and ammonium sulfate, the content of NH4+-N in the leaves of each plant was lower when potassium nitrate was used as the nitrogen source. The qPCR results showed that OsGS and OsNGS1 were negatively regulated by downstream metabolites, and OsNrt2.2 was induced by nitrate. In summary, when ammonium nitrate served as the nitrogen source, the weak growth of NIA1 phosphorylation site-directed mutant lines was due to the toxicity caused by the excessive accumulation of nitrite. When potassium nitrate served as the nitrogen source, the assimilation rates of nitrate, nitrite and ammonium salt were accelerated in NIA1 phosphorylation site-directed mutant lines, which could provide more nitrogen nutrition and improve the tolerance of rice to ammonium nitrogen deficiency. These results could provide a possible method to improve the efficiency of nitrogen utilization in rice under low-nitrogen conditions.  相似文献   

12.
Nitrogen is an important nutrient for plant development. Nitrogen and carbon metabolisms are tightly linked to physiological functions in plants. In this study, we found that the IbSnRK1 gene was induced by Ca(NO3)2. Its overexpression enhanced nitrogen uptake and carbon assimilation in transgenic sweetpotato. After Ca(15NO3)2 treatment, the 15N atom excess, 15N and total N content and nitrogen uptake efficiency (NUE) were significantly increased in the roots, stems, and leaves of transgenic plants compared with wild type (WT) and empty vector control (VC). After Ca(NO3)2 treatment, the increased nitrate N content, nitrate reductase (NR) activity, free amino acid content, and soluble protein content were found in the roots or leaves of transgenic plants. The photosynthesis and carbon assimilation were enhanced. These results suggest that the IbSnRK1 gene play a important role in nitrogen uptake and carbon assimilation of sweetpotato. This gene has the potential to be used for improving the yield and quality of sweetpotato.  相似文献   

13.
不同基因型高粱的氮效率及对低氮胁迫的生理响应   总被引:3,自引:1,他引:2  
【目的】探讨不同基因型高粱氮素吸收效率和利用效率及其差异机制,研究低氮胁迫对不同基因型高粱叶片无机氮含量和氮同化酶活性的影响,为耐低氮型高粱品种的选育提供理论依据。【方法】采用盆栽试验,选取2个低氮敏感型高粱(冀蚜2号和TX7000B)和2个耐低氮型高粱(SX44B和TX378)为试验材料,设置高氮(0.24g·kg-1风干土)和低氮(0.04 g·kg-1风干土)2个处理,分别在挑旗期和灌浆期测定高粱叶片NO3--N、NO2--N及NH4+-N含量和硝酸还原酶(NR)、亚硝酸还原酶(Ni R)、谷氨酰胺合成酶(GS)和谷氨酸合成酶(GOGAT)活性,分析不同基因型高粱在2个氮处理下的氮效率相关指标及其差异。【结果】(1)不同基因型高粱籽粒产量对低氮的响应不同,低氮处理显著降低了冀蚜2号和TX7000B的籽粒产量,与高氮处理比较分别降低13.87%和19.25%,但没有降低SX44B和TX378的籽粒产量。(2)与高氮处理比较,低氮处理的相对籽粒氮累积量、相对植株氮累积量和相对氮收获指数不能表征各基因型高粱是否具有耐低氮特性;但相对低氮敏感型高粱,耐低氮型高粱在低氮处理下有着较高的相对氮肥偏生产力和相对氮素利用效率。低氮处理下SX44B和TX378的氮肥偏生产力是高氮处理的6.19和7.49倍,而冀蚜2号和TX7000B则分别为5.17和4.85倍;低氮处理下SX44B和TX378的氮素利用效率是高氮处理的1.84和1.85倍,而冀蚜2号和TX7000B则分别为1.67和1.35倍。(3)通径分析表明,高氮处理下,植株氮累积量和氮素利用效率对籽粒产量贡献相同;而在低氮处理下,氮素利用效率对籽粒产量关联作用更大。(4)高粱的叶片无机氮含量不能表征高粱是否具有耐低氮特性,灌浆期叶片无机氮含量较挑旗期显著降低。(5)与高氮处理比较,低氮处理时冀蚜2号和TX7000B叶片中NR、GS和GOGAT活性显著降低,SX44B酶活性变化不显著,而TX378叶片中GS活性增加。【结论】耐低氮型高粱在低氮胁迫时有着较高的相对籽粒产量和相对氮素利用效率。低氮胁迫时叶片较高的氮同化酶活性是高粱耐低氮的生理基础。发掘和利用低氮条件下具有较高的叶片氮同化酶活性和氮素利用效率的高粱种质资源,有助于提高耐低氮高粱品种的培育效率。  相似文献   

14.
内生菌-植物联合修复污染土壤研究进展   总被引:1,自引:0,他引:1  
环境污染对生态系统及人类健康造成严重威胁。近年来,许多学者研究发现内生菌联合植物修复体系对修复自然环境中的重金属和有机物具有巨大的潜力。本文主要从内生菌联合植物进行污染修复的机理和应用两方面入手,介绍了内生菌接种宿主植物根、茎、叶部的几种方法及定殖的检测方法,总结了污染土壤中内生菌在植物组织内的定殖动态,以及内生菌-植物联合体系强化有机物污染和重金属污染修复效果的应用,并从内生菌调节生长因子、生物固氮和溶磷、在宿主植物体内的共代谢有机物、产生特异性酶降解有机物、提升植物对重金属抗性和降低重金属毒性几个方面解释了内生菌和植物的联合修复机理。最后指出,虽然已经有许多对于内生菌联合植物修复体系的研究,但是目前两者相互作用机理尚未完全清楚,对于多种内生菌组合体系以及处理水体和大气污染的研究并不完善,这些都将成为今后的研究重点。  相似文献   

15.
药用植物内生菌及其产生的活性成分研究现状   总被引:2,自引:0,他引:2  
药用植物内生茵具有合成与宿主植物相同或相似活性成分的功能,在生物防治、医药卫生等领域有着广阔的前景。从内生茵对药用植物活性成分产生和积累的影响、药用植物内生茵产生的活性成分的作用、研究内生茵与药用植物活性成分的关联性的途径等方面进行了综述,提出了内生菌研究过程中待解决的若干问题,为进一步研究药物植物内生茵提供参考。  相似文献   

16.
High nitrate(NO_3~- ) in vegetables, especially in leaf vegetables poses threaten to human health. Selenium(Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies. Exogenous Se shows positive function on plant growth and nutrition uptake under abiotic and/or biotic stresses. However, the influence of exogenous Se on NO_3~- accumulation in hydroponic vegetables is still not clear. In the present study, hydroponic lettuce plants were subjected to six different concentrations(0, 0.1, 0.5, 5, 10 and 50 μmol L–1) of Se as Na2 Se O3. The effects of Se on NO_3~- content, plant growth, and photosynthetic capacity of lettuce(Lactuca sativa L.) were investigated. The results showed that exogenous Se positively decreased NO_3~- content and this effect was concentration-dependent. The lowest NO_3~- content was obtained under 0.5 μmol L–1 Se treatment. The application of Se enhanced photosynthetic capacity by increasing the photosynthesis rate(Pn), stomatal conductance(Cs) and the transpiration efficiency(Tr) of lettuce. The transportation and assimilation of NO_3~- and activities of nitrogen metabolism enzymes in lettuce were also analysed. The NO_3~- efflux in the lettuce roots was markedly increased, but the efflux of NO_3~- from the root to the shoot was decreased after treated with exogenous Se. Moreover, Se application stimulated NO_3~- assimilation by enhancing nitrate reductase(NR), nitrite reductase(Ni R), glutamine synthetase(GS) and glutamate synthase enzyme(GOGAT) activities. These results provide direct evidence that exogenous Se shows positive function on decreasing NO_3~- accumulation via regulating the transport and enhancing activities of nitrogen metabolism enzyme in lettuce. We suggested that 0.5 μmol L–1 Se can be used to reduce NO_3~- content and increase hydroponic lettuce yield.  相似文献   

17.
以药用植物长春花( Catharanthus roseus ( L.) G.Don)为对象,研究不同形态外源氮供应条件下,长春花生长发育与体内氮代谢响应盐胁迫的变化特点。结果表明,无盐胁迫条件下,不同形态氮源供应对长春花生长影响不显著,但硝态氮与氨态氮混合供应的情况下,硝酸还原酶( NR)和谷氨酰胺合成酶( GS)的活性及游离氨基酸总质量分数显著高于其他氮源条件下的;在盐胁迫条件下,硝态氮和氨态氮混合供应显著增加了叶片生物量积累,同时,NR活性也显著提高。总体上,混合氮源供应可以减少盐胁迫对长春花的伤害。这种作用可能与氮代谢过程中关键酶活性的增加有关,特别是与氨代谢有关的酶有关,适量的氨离子可以节省植物代谢硝态氮的能量。  相似文献   

18.
Dopamine plays numerous physiological roles in plants. We explored its role in the regulation of growth, nutrient absorption, and response to nitrogen (N) deficiency in Malus hupehensis Rehd. Under low N condition, plant growth slowed, and the net photosynthetic rates, chlorophyll contents, and maximal quantum yield of PSII (Fv/Fm) decreased significantly. However, the application of 100 μmol L−1 exogenous dopamine significantly reduced the inhibition of low N stress on plant growth. In addition to modifying root system architecture under low N supply, exogenous dopamine also changed the uptake, transport, and distribution of N, P, and K. Furthermore, exogenous dopamine enhances the tolerance to low nitrogen stress by increasing the activity of enzymes (nitrate reductase, nitrite reductase, glutamic acid synthase and glutamine synthetase) involved in N metabolism. We also found that exogenous dopamine promoted the expression of ethylene signaling genes (ERF1, ERF2, EIL1, ERS2, ETR1, and EIN4) under low N stress. Therefore, we hypothesized that ethylene might be involved in dopamine response to low N stress in M. hupehensis. Our results suggest that exogenous dopamine can mitigate low N stress by regulating the absorption of mineral nutrients, possibly through the regulation of the ethylene signaling pathway.  相似文献   

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为探讨人工湿地各组分氮素削减贡献度及微生物脱氮机理,本研究构建6组(3组无植物对照)不同类型人工湿地系统,3组有植物人工湿地基质分别为陶粒+煤渣、陶粒+沸石、沸石+煤渣,探究其对包头南海湖水中氮素的去除效果;采用氮稳定同位素示踪技术,量化植物、基质和微生物在人工湿地氮去除中的贡献度;并利用高通量测序技术分析人工湿地系统中微生物的群落结构及氮代谢功能基因。结果表明:陶粒+煤渣有植物组人工湿地氮去除效果最佳,对TN、NH4+-N、NO3--N、NO2--N的去除率分别为(41.18±2.61)%、(50.44±2.63)%、(40.93±2.32)%、(74.34±1.97)%。15N示踪发现,植物、基质和微生物对人工湿地系统NO3--N去除的贡献率分别为27.74%、48.43%和23.83%。高通量测序和PICRUSt2功能预测分析结果表明,植物对微生物群落组成和代谢途径有显著影响。在植物根...  相似文献   

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