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1.
脱落酸对干旱胁迫下茶树生理特性的影响   总被引:2,自引:0,他引:2  
脱落酸(Abscisic acid,ABA)是一种重要的植物激素,在植物对胁迫耐受性和抗性中发挥着重要作用。以茶树品种迎霜为材料,分别采用100 mg·mL-1、200 mg·mL-1聚乙二醇6000(PEG 6000)模拟干旱胁迫,研究了外源ABA对干旱胁迫下茶树叶片生理生化特性的影响。结果表明:喷施外源ABA后,渗透调节物质含量和抗氧化酶活性略有提高。干旱胁迫下,外源ABA能提高茶树体内脯氨酸、可溶性糖及可溶性蛋白含量,同时增强了抗氧化酶活性,从而降低干旱胁迫对茶苗的伤害。经ABA处理后的茶苗在复水后,渗透调节物质含量和抗氧化酶活性均保持较高值,外源ABA对提高茶树抗旱性起到一定的作用。  相似文献   

2.
研究外源 NO 对干旱胁迫生理生化反应。以15%聚乙二醇(PEG 6000)模拟干旱胁迫,0.5 mmol·L-1的外源 NO 供体(SNP)处理对茶树幼苗叶片游离脯氨酸、丙二醛(MDA)的含量及保护酶活性的影响。结果表明,一定浓度的 SNP 缓解干旱胁迫伤害的效果较好,显著提高了受干旱胁迫茶树幼苗叶片的保护酶(CAT)活性和游离脯氨酸含量,并降低了 MDA 的含量。表明外源 NO 通过提高干旱胁迫下渗透调节物质含量和保护酶活性,降低 MDA 的含量,缓解干旱胁迫对茶树幼苗的损伤,增强植株的抗旱性。  相似文献   

3.
Identification of genetic factors controlling traits associated with seed germination under drought stress conditions, leads to identification and development of drought tolerant varieties. Present study by using a population of F2:, derived from a cross between a drought tolerant variety, Gharib (indica) and a drought sensitive variety, Sepidroud (indica), is to identify and compare QTLs associated with germination traits under drought stress and non-stress conditions. Through QTL analysis, using composite interval mapping, regarding traits such as germination rate (GR), germination percentage (GP), radicle length (RL), plumule length (PL), coleorhiza length (COL) and coleoptile length (CL), totally 13 QTLs were detected under pole drought stress (-8 MPa poly ethylene glycol 6000) and 9 QTLs under non-stress conditions. Of the QTLs identified under non-stress conditions, QTLs associated with COL (qCOL-5) and GR (qGR-1) explained 21.28% and 19.73% of the total phenotypic variations, respectively Under drought stress conditions, QTLs associated with COL (qCOL-3) and PL (qPL-5) explained 18.34% and 18.22% of the total phenotypic variations, respectively. A few drought-tolerance-related QTLs identified in previous studies are near the QTLs detected in this study, and several QTLs in this study are novel alleles. The major QTLs like qGR-1, qGP-4, qRL-12 and qCL-4 identified in both conditions for traits GR, GP, RL and CL, respectively, should be considered as the important and stable trait-controlling QTLs in rice seed germination. Those major or minor QTLs could be used to significantly improve drought tolerance by marker-assisted selection in rice.  相似文献   

4.
Drought tolerance levels and antioxidant protection mechanisms were evaluated for 21 traditional rice varieties of Assam, India, along with Sahbhagi Dhan (drought tolerant) and IR64 (drought sensitive) as controls. Drought was imposed in hydroponic culture with polyethylene glycol 6000 (PEG6000) that was initially standardized with different concentrations. All the rice varieties showed apparent decreases in growth characteristics under drought stress (initially at 15% for 7 d followed by 20% PEG6000 for 7 d in Yoshida medium). On the basis of standard evaluation score (SES), eight rice varieties showed high drought tolerance which were carried forward for further biochemical analyses. Based on different morpho- physiological parameters, SN03 (Bora), SN04 (Prosad Bhog), SN05 (Kola Joha), SN06 (Helash Bora), SN08 (Salihoi Bao), SN12 (Kola Amona), SN20 (Ronga Bora) and SN21 (Sok-Bonglong) were identified as promising drought tolerant varieties. The non-enzymatic antioxidants activities viz., glutathione, ascorbate and enzymatic antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), glutathione reductase (GR) in shoots and roots of all the selected varieties revealed significant level of protection mechanisms as compared with controls. Enhancement in activities of the overall antioxidant enzymes including SOD, GPX, CAT, GR and APX under drought stress reflects their role in the adaptation process under water stress.  相似文献   

5.
Drought is the major abiotic stress factor that limits rice production worldwide.To evaluate the osmotic stress responses in rice varieties under drought condition,a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India.The experimental setup comprises of initial hydroponic treatments at different osmotic potentials,artificially induced by desired strengths of polyethylene glycol(PEG6000),and followed by the pot planted experiments in the rain-out-zone.The activities of antioxidant enzymes,relative water content,cell membrane stability,photosynthetic pigments,proline content,along with plant growth parameters of the varieties under drought condition were evaluated.Moreover,the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice.Among the 42 rice varieties,we identified 2 rice varieties,Swarnaprabha and Kattamodan,with less leaf rolling,better drought recovery ability as well as relative water content,increased membrane stability index,osmolyte accumulation,and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress.The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program.  相似文献   

6.
采用10%聚乙二醇(PEG-6000)模拟干旱胁迫的方法,研究其对14个甘蓝型油菜品种发芽期生理生化性状的影响。结果表明,PEG-6000模拟干旱胁迫后,幼苗的相对活力指数在0.32-0.79之间,14个品种的平均相对活力指数为0.49。干旱胁迫后,14个油菜品种的平均苗高比对照降低40.68%,平均单株鲜重比对照降低34.2%,平均成苗率比对照降低18%。但干旱胁迫对根系生长的影响差异不显著。PEG-6000模拟干旱胁迫后,幼苗丙二醛(MDA)、可溶性糖、脯氨酸、可溶性蛋白的含量和电导率均比对照极显著提高,丙二醛的平均含量比对照提高96.7%,可溶性糖平均含量比对照提高75.0%,脯氨酸平均含量比对照增加2204.9%,可溶性蛋白的平均含量比对照增加56.2%,平均电导率比对照增加34.8%。在各种指标中,相对活力指数较为直观、综合地反映了发芽和生长性状,可作为油菜发芽期抗旱鉴定的主要指标。  相似文献   

7.
Three popular traditional rice landraces, namely Kalajeera, Machakanta and Haladichudi, from Koraput, India were used to analyse the leaf traits and antioxidant defence for drought tolerance. When rice plants were exposed to different levels of drought stress by varying concentrations of polyethylene glycol(PEG) 6000, seed germination and growth parameters were significantly declined in all the rice landraces compared to the control. Drought stress also altered the leaf phenotypic traits based on chlorophyll fluorescence parameters and chlorophyll index, with more significant differences in susceptible variety IR64 than in traditional landraces. Furthermore, activities of antioxidative enzymes and proline and protein contents overtly increased under drought stress. The traditional rice landraces showed higher relative ratios for different parameters compared to the susceptible variety IR64. Taken together,the traditional landraces had superior leaf physiological efficiency compared to the susceptible and tolerant check varieties under drought stress.  相似文献   

8.
There are several mechanisms used by plants for survival in adverse environments such as drought, high temperature and salinity. The objective of this study was to evaluate the drought tolerance of tepary bean as a function of biochemical processes linked to isozyme synthesis and changes in enzymatic activity related to proline metabolism. Mature seeds of common beans var. flor de mayo, Phaseolus vulgaris and tepary beans Phaseolus acutifolius were grown under two water conditions (irrigation and drought), and four levels of urea. Vertical electrophoresis and spectrophotometric techniques were used to evaluate protein patterns, glutamate dehydrogenase (GDH), proline oxidase (PO) and pyrroline-5-carboxylate reductase (P5C reductase) enzyme activities. These enzymes were studied because they are directly related to protein synthesis. Electrophoretic patterns showed more proteins in tepary beans than in common beans with limited irrigation. GDH showed only one isozyme, with a molecular weight between 240 to 270 kDa. A decrease in PO activity was observed in common beans under drought stress with a value of 237 mol/min, in comparison to irrigation conditions of 580 mol/min. GDH and P5C reductase enzymes have had higher activity in common beans than in tepary beans under water stress. There was a significant difference only in glutamate dehydrogenase enzyme with respect to urea level. The results suggest that drought tolerance of tepary beans is due to biochemical processes related to proline metabolic enzymes.  相似文献   

9.
10.
西南麦区小麦品种萌发期抗旱性的综合鉴定及评价   总被引:3,自引:0,他引:3  
为筛选西南麦区小麦萌发期抗旱性强的品种,用20% PEG-6000水溶液模拟干旱胁迫,测定41个小麦品种的发芽势、发芽率、发芽指数、苗高、胚芽鞘长度、胚根长、胚根数等性状,并通过加权隶属函数法对供试材料的抗旱性进行综合评价.结果表明,与正常条件相比,20% PEG-6000胁迫下小麦种子胚根数均降低(西科麦5号和川麦104例外),发芽势、发芽率、发芽指数、苗高、胚芽鞘长度、根长均受到抑制,且不同品种降幅不同.通过加权隶属函数法分析,综合评价值(D值)较大的前五位品种分别是蜀万8号、绵麦228、绵麦37、川麦104和内麦316.利用聚类分析对41个品种的抗旱性进行分类,蜀万8号、绵麦37等5个品种为高度抗旱品种;川麦60、昌麦30等13个品种为抗旱品种;内麦9号、川麦43等10个品种为中等抗旱品种;绵阳26、蜀麦482等8个品种为对水分胁迫敏感品种;川麦55、川麦42等5个品种为对水分胁迫高度敏感品种.除根长外,其他鉴定指标与D值呈极显著正相关,发芽率和发芽指数与D值的相关系数最大(0.87).发芽率和发芽指数可作为小麦萌发期抗旱性快速鉴定的参考指标.强抗旱性品种蜀万8号、绵麦37、绵麦228等可作为西南麦区小麦抗旱育种种质资源.  相似文献   

11.
Leaf rolling is one of the most significant symptoms of drought stress in plant. Previously, we identified a dominant negative mutant, termed rolled and erect 1 (hereafter referred to rel1-D), regulating leaf rolling and erectness in rice. However, the role of REL1 in drought response is still poorly understood. Here, our results indicated that rel1-D displayed higher tolerance to drought relative to wild type, and the activity of superoxide dismutase (SOD) and drought responsive genes were significantly up-regulated in rel1-D. Moreover, our results revealed that rel1-D was hypersensitive to ABA and the expression of ABA associated genes was significantly increased in rel1-D, suggesting that REL1 likely coordinates ABA to regulate drought response. Using the RNA-seq approach, we identified a large group of differentially expressed genes that regulate stimuli and stresses response. Consistently, we also found that constitutive expression of REL1 alters the expression of biotic and abiotic stress responsive genes by the isobaric tags for relative and absolute quantification (iTRAQ) analysis. Integrative analysis demonstrated that 8 genes/proteins identified by both RNA-seq and iTRAQ would be the potential targets in term of the REL1-mediated leaf morphology. Together, we proposed that leaf rolling and drought tolerance of rel1-D under normal condition might be caused by the endogenously perturbed homeostasis derived from continuous stressful dynamics.  相似文献   

12.
为了解野生二粒小麦响应干旱胁迫的调控机制,分析了干旱胁迫下小麦根的相对含水量、丙二醛、脯氨酸和过氧化氢含量,采用双向电泳(2-DE)结合MALDI-TOF-TOF-MS方法分离和鉴定了野生二粒小麦根中干旱响应蛋白的变化。结果表明,随着干旱处理时间的延长,野生二粒小麦根的相对含水量下降,脯氨酸含量先上升后降低,过氧化氢含量和丙二醛含量上升;复水后的野生二粒小麦根的相对含水量、脯氨酸含量有所升高,但未达到对照的水平。通过对干旱处理6d后根系的总蛋白进行双向电泳分离和MALDI-TOFTOF生物质谱鉴定,成功鉴定出26个差异表达蛋白,13个上调表达,13个下调表达。26个差异表达蛋白的功能主要涉及信号传导、氧化解毒、碳代谢、能量代谢、蛋白质生物合成及细胞骨架稳定。推测野生二粒小麦为适应干旱胁迫,通过根部感应胁迫信号,并传导至细胞内,影响小麦根中蛋白质的生物合成、氨基酸代谢、碳水化合物代谢、细胞骨架形成;通过抗氧化酶系统和抗氧化物质的作用,将过多活性氧加以清除;通过增加胞内脯氨酸含量,降低根中水分损失。  相似文献   

13.
以早稻品种瑰宝8号及其耐低钾变异后代为材料,用20%PEG6000模拟干旱胁迫,测定丙二醛(MDA)含量、脯氨酸(Pro)含量、超氧化物歧化酶(SOD)活性及质膜相对透性。模拟干旱胁迫后,MDA、Pro含量和质膜相对透性呈急剧上升的趋势,瑰宝8号中的MDA、Pro含量显著高于它的变异后代;SOD活性先迅速上升后急剧下降,变异后代的SOD活性始终高于瑰宝8号。相关性分析表明,Pro含量与MDA含量和质膜相对透性呈显著正相关,而与SOD活性呈一定程度的负相关。  相似文献   

14.
We studied the influence of seed priming with beta-amino butyric acid(BABA) on the growth, physiological and biochemical parameters of seedlings with varied abiotic stress tolerance, which were raised and grown under unstressed and stressed(NaCl/PEG-6000) conditions. Under stressed conditions, the growth of rice seedlings was less when compared to control plants. After BABA priming, the seedling growth increased both under unstressed and stressed conditions as compared to the respective controls. BABA priming of rice seeds caused increase in the photosynthetic pigment content of the leaves, modified the chlorophyll a fluorescence related parameters and also enhanced the photosystem activities of seedlings when compared to their respective non-primed controls. BABA priming also caused increased mitochondrial activities of the rice seedlings. Moreover, BABA priming significantly reduced malondialdehyde content in the seedlings and also resulted in accumulation of proline especially in the NaCl tolerant variety Vyttila 6. BABA seed priming also enhanced the activity of nitrate reductase enzyme and activities of antioxidant enzymes like guaiacol peroxidase and superoxide dismutase. The presence of BABA was detected by high performance thin layer chromatography analysis in the rice seeds whereas in the seedlings it was not detected. Thus, it can be inferred that the seed priming effect of BABA mainly occurred within the seeds, which was further carried to the seedlings. It is concluded that BABA priming of seeds improved the drought and salinity stress tolerance of all the three rice varieties and it was significantly evident in the drought tolerant variety Vaisakh and NaCl tolerant variety Vyttila 6, when compared to the stress sensitive variety Neeraja.  相似文献   

15.
Drought tolerance is an important rainfed rice breeding objective, but because the heritability (H) of yield under drought stress is thought to be low, secondary physiological traits are considered better targets for selection than yield under stress per se. This assumption has rarely been tested, and there are no reports on H for yield under drought stress from experiments repeated over seasons in rainfed lowland rice. To assess the potential for improving yield under drought stress via direct selection, and to identify associated quantitative trait loci (QTL), doubled haploid lines with a narrow range of flowering dates, derived from the population CT9993-5-10-1-M/IR62266-42-6-2, were screened under full irrigation and severe drought stress induced by draining the paddy before flowering in 2000–2002 at Raipur, India. Drought stress reduced mean yield by 80%. H was similar in stress and non-stress trials, as was the relative magnitude of the genotype and genotype × year variances. The genetic correlation between yield in stress and non-stress conditions was 0.8, indicating that about 64% of the genetic variation for yield under stress was accounted for by differences in yield potential also expressed in irrigated environments. These results indicate that direct selection for yield under drought stress can produce yield gains under stress without reducing yield potential. There was no secondary trait for which selection resulted in greater predicted response in yield under stress than direct selection for stress yield per se. A QTL was detected on chromosome 1 near sd1 that explained 32% of the genetic variation for yield under stress, but only 4% under non-stress. Its effect was consistent across years. This QTL accounted for much of the variation in drought yield not accounted for by variation in yield potential.  相似文献   

16.
为了探讨多胺提高小麦抗旱性的机理,以两个抗旱性不同的小麦品种(豫麦48,抗旱性较弱;洛麦22,抗旱性较强)为材料,研究了亚精胺对短期渗透胁迫下小麦幼苗叶片渗透调节物质含量以及脯氨酸代谢的调控效应。结果表明,渗透胁迫下,两个小麦品种幼苗叶片中脯氨酸、葡萄糖和蔗糖含量增加,且抗旱性较强的洛麦22增加幅度显著大于抗旱性较弱的豫麦48;脯氨酸代谢关键酶Δ1-吡咯啉-5-羧酸合成酶(P5CS)和Δ1-吡咯啉-5-羧酸还原酶(P5CR)活性增强,且洛麦22的P5CS活性增强幅度大于P5CR。但渗透胁迫处理对两个品种鸟氨酸转氨酶(OAT)活性影响不大。外源亚精胺处理则进一步提高了渗透胁迫下脯氨酸、葡萄糖、蔗糖含量以及P5CS和P5CR活性,且对抗旱性较弱的豫麦48效应较明显,但对两个品种的OAT活性基本没什么影响。这些结果表明,外源亚精胺处理能通过提高脯氨酸合成代谢谷氨酸途径的关键酶P5CS和P5CR的活性促进脯氨酸和可溶性糖的积累,从而提高小麦幼苗的保水性,增强其抗旱性,对抗旱性较弱的小麦品种的效果更加明显。  相似文献   

17.
Nine CBF/DREB1 homologous genes in rice were obtained by BLAST search in the NCBI database,which share conserved amino acid sequences with DREB1 protein in Arabidopsis.Three CBF genes organized in tandem,named OsCBF1,OsCBF2 and OsCBF3,showed a transient induction in the process of cold acclimation,much stronger in indica rice 93-11 compared with japonica rice Nipponbare.The candidate downstream genes OsLIP5 and OsLIP9 were induced in 93-11 but not in Nipponbare.The differential expression of CBF regulon might be caused by polymorphisms within promoter sequences between these two rice varieties.These results could be useful for utilization of CBF/DREB1 genes and illustration of differences in chilling tolerance between indica and japonica rice varieties.  相似文献   

18.
PEG模拟干旱胁迫下甘蓝型油菜的根系特性与抗旱性   总被引:4,自引:0,他引:4  
采用砂培法,利用14%(m/V)聚乙二醇(PEG-6000)模拟干旱胁迫,研究39份甘蓝型油菜发芽期根系性状的变化及其与抗旱性的关系。结果表明,干旱胁迫对油菜根鲜重和侧根数有明显的抑制作用,而对根长和根冠比的影响较小。相关分析表明,相对侧根数与活力指数之间以及根长与活力指数之间均呈显著正相关,可作为抗旱性鉴定的辅助指标。杂交种和常规种在根系性状上差别不显著,表明其抗旱能力相当。对油菜的抗旱性进行综合评价和聚类分析发现,在欧式距离为60时39份材料可分为5个类群,其中A类抗旱性最强,平均相对侧根数77.9%,相对根长98.9%;E类抗旱性最差,平均相对侧根数69.3%,相对根长84.5%。筛选出发芽期抗旱性较强的3份材料:OR918、OR805和OR2025。    相似文献   

19.
抗逆相关bZIP (Basic leucine zipper) 转录因子家族基因主要参与ABA、干旱、高盐等胁迫应答反应,其过表达能够显著增强植物的抗逆性。本研究从偃麦草(Elytrigria repens L.)中分离到一个抗逆相关 ErABF1E. repens ABA Binding Factor 1)基因,氨基酸序列比对分析发现,该基因与小麦、玉米、拟南芥等bZIP转录因子基因同源性较高,亲缘关系较近;ErABF1基因的表达受到ABA、干旱、高盐、低温的强烈诱导;在2% PEG、200 mmol·L-1 NaCl胁迫培养基上初步功能分析表明, ErABF1过表达提高了转基因烟草对干旱、高盐的胁迫耐性。  相似文献   

20.
Coleoptile lengths of 7-day-old seedlings under anoxic stress and normal conditions were investigated in two permanently segregated populations and their parents in rice (Oryza sativa L.). Using anoxic response index, a ratio of coleoptile length under anoxic stress to coleoptile length under normal conditions, as an indicator of seedling anoxic tolerance (SAT), QTLs for SAT were detected. Two loci controlling SAT, designated as qSAT-2-R and qSAT-7-R, were detected in a recombinant inbred line (RIL) population (247 lines) derived from a cross between Xiushui 79 (japonica variety) and C Bao (japonica restorer line). qSAT-2-R, explaining 8.7% of the phenotype variation, was tightly linked with the SSR marker RM525. qSAT-7-R, explaining 9.8% of the phenotype variation, was tightly linked with the marker RM418. The positive alleles of the two loci came from C Bao. Six loci controlling SAT, designated as qSAT-2-B, qSAT-3-B, qSAT-5-B, qSAT-8-B, qSAT-9-B and qSAT-12-B, were detected in a backcross inbred line (BIL) population (98 lines) derived from a backcross of Nipponbare (japonica)/Kasalath (indica)//Nipponbare (japonica). The positive alleles of qSAT-2-B, qSAT-3-B and qSAT-9-B, which explained 16.2%, 11.4% and 9.5% of the phenotype variation, respectively, came from Nipponbare. Besides, the positive alleles of qSAT-5-B, qSAT-8-B and qSAT-12-B, which explained 7.3%, 5.8% and 14.0% of the phenotype variation, respectively, were from Kasalath.  相似文献   

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