XRN4/EIN5调控拟南芥对盐胁迫和ABA的耐受性

XRN4/EIN5是植物的5′-3′核酸外切酶,主要参与细胞质中RNA的降解,同时也是乙烯信号通路的核心基因,在植物的生长发育和乙烯信号转导中起着重要作用。为探究该基因在植物抗逆性方面的作用,以XRN4/EIN5 T-DNA插入突变体ein5-6为材料,设计不同浓度NaCl(0、50、100、150、200 mmol/L)和ABA(0、0.10、0.25、0.50、1.00、1.50μmol/L)处理,基于拟南芥种子发芽率、子叶绿化率、叶片数、叶片面积进行统计分析,结果发现,当盐浓度低于50 mmol/L时,ein5-6的种子发芽率、子叶绿化率、叶片数和叶片面积比野生型Col-0高;当盐浓度达到100 mmol/L时,ein5-6的种子发芽率和子叶绿化率在发育前期比Col-0高,60 h和96 h之后比Col-0低,而二者的叶片数和叶片面积没有差异;当盐浓度达到150 mmol/L及以上时,ein5-6的种子发芽率、子叶绿化率、叶片数和叶片面积比Col-0低。另外,ein5-6对ABA与盐胁迫响应的趋势一致,ABA浓度较低时ein5-6的子叶绿化率高于Col-0,但随着处理时间的延长和ABA浓度的增加,其子叶绿化率越来越低,最终明显低于Col-0。表明与野生型相比,ein5-6对盐胁迫和ABA处理更敏感,推测XRN4/EIN5参与了盐胁迫和ABA响应的调节。

转录组测序分析梨种子催芽过程涉及ABA通路的关键基因

种子休眠与萌发受到内源激素和外界环境等多种因素的调控。生产上常采用清水浸泡和低温砂藏层积处理方法打破梨种子休眠进程,促进种子萌发。为解析梨种子休眠解除的分子机制,以翠冠梨干种子为研究对象,通过清水浸泡6 h再低温砂藏60 d进行催芽。对该过程17个时期种仁ABA含量进行测定,结果显示在种子浸泡过程和低温砂藏7 d阶段ABA含量整体呈现下降趋势,随后趋于稳定。选取其中7个关键时期样品进行转录组测序,GO分析结果显示差异基因被分配到40个功能组,KEGG分析结果显示差异基因主要富集在核糖体、多样化环境中微生物代谢、碳代谢、辅因子的生物合成和氨基酸的生物合成通路。通过转录组测序获得的基因FPKM值和ABA含量数据构建共表达网络,结果显示11个基因(Pbr009501、Pbr016256、Pbr011612、Pbr033750、Pbr015393、Pbr000885、Pbr037755、Pbr039726、Pbr020341、Pbr003677和Pbr015873)与ABA含量的相关性均极高,相关性系数达到0.91~0.96。研究结果为挖掘梨种子休眠和萌发过程调控ABA水平的关键基因提供了重要信息。

代谢组和转录组联合解析青花菜芽苗黄酮类物质对外源ABA的响应机制

为探究植物激素脱落酸对青花菜芽苗黄酮类物质合成的作用机制,以青花菜品种耐寒优秀为试材,以清水为对照,外源喷施50μmol·L^(-1)的ABA,对处理后的青花菜芽苗进行代谢组和转录组的联合分析。结果表明,代谢组共检测出14类物质,包含黄酮共212种,具有明显差异的黄酮共30种。其中,儿茶素没食子酸酯、表儿茶素没食子酸酯和桑色素含量明显上升,柚皮苷、银锻苷和枸橘苷含量明显下降。通过代谢组和转录组联合分析,黄酮合成途径、苯丙烷合成途径以及ABA信号通路共筛选出13个相关调控基因,其中LOC106337270、LOC106329559、LOC106326133对儿茶素没食子酸酯、表儿茶素没食子酸酯和桑色素含量呈明显正相关,推测上述基因可响应ABA信号参与调控黄酮类化合物的生物合成。综上所述,研究结果表征了青花菜芽苗响应外源ABA并调控黄酮类化合物合成的关键基因,为后续黄酮类化合物的生物合成调控奠定了科学理论基础。

旱柳失水枝条中ABA介导的代谢组响应分析

【目的】ABA是植物干旱胁迫的关键激素,通过代谢组学分析揭示旱柳离体枝条ABA介导的失水响应差异代谢物及其相关通路,为旱柳干旱胁迫响应提供研究基础和理论依据。【方法】以旱柳离体枝条为材料,探究ABA合成抑制剂钨酸钠溶液浸泡后旱柳失水至不同水势枝条木质部代谢组的差异响应。【结果】失水至P50(-1.9 MPa)旱柳枝条代谢组与未失水枝条相比,内源ABA含量显著增加了425.032%,D-果糖等可溶性糖含量与L-谷氨酸等氨基酸含量显著增加。ABA抑制剂处理后内源ABA含量显著降低了79.253%,D-1,5-脱水果糖等可溶性糖含量与苯丙氨酸等氨基酸含量显著降低。植物激素信号转导、类胡萝卜素生物合成和淀粉与蔗糖代谢途径等是旱柳枝条失水响应的关键代谢通路。【结论】旱柳枝条失水后ABA含量显著增加,介导多糖水解过程等降低了细胞渗透势以应对干旱胁迫。

NaCl胁迫下宁夏枸杞ABA代谢相关基因差异表达分析

为解析宁夏枸杞响应NaCl胁迫的ABA代谢分子调控机制,检测NaCl胁迫下宁夏枸杞叶片脱落酸(ABA)含量变化,并利用RNA-seq和qRT-PCR技术研究NaCl胁迫下ABA代谢相关基因的差异表达规律。结果表明,不同浓度NaCl胁迫下,宁夏枸杞叶片中ABA含量随NaCl浓度的增加呈现增加趋势;通过转录组测序筛选得到21个ABA代谢相关的差异表达基因,从100 mmol/L、200 mmol/L、300 mmol/L NaCl处理下的宁夏枸杞叶片中检测到ABA代谢相关的差异表达基因分别有17、11、9个,qRT-PCR检测结果与转录组测序结果基本一致。宁夏枸杞通过相关基因的差异表达调控ABA代谢和信号通路,从而参与调控其响应NaCl胁迫。

外源ABA、ZR及IAA对甘薯脱毒苗生长及结薯的影响

以甘薯品种龙薯9号的脱毒试管苗为试验材料,采用盆栽基质培养、向根部营养液加入植物激素的处理方式,设置单因素试验,分别探究了0(CK)、0.7、7.0、14.0 mg/L的ABA与IAA,以及0(CK)、0.8、8.0、16.0 mg/L ZR对脱毒苗根生长发育及结薯的影响。结果表明:0.8 mg/L ZR处理的单株结薯数和单株薯重分别较CK提高2.25个和5.93 g;0.7 mg/L ABA处理的单株结薯数和单株薯重分别较CK提高2.00个和5.43 g;14 mg/L IAA处理可显著增加脱毒苗的根长和茎长。综上所述,在脱毒薯生产过程中,根部施加0.7 mg/L ABA或0.8 mg/L ZR均可显著增加脱毒苗的单株结薯数和单株薯重,根部添加14 mg/L IAA可显著促进脱毒苗根与茎的伸长。本试验结果可为脱毒种薯种苗高效生产提供技术支撑。

Involvement of the ABA-and H_(2)O_(2)-Mediated Ascorbate-Glutathione Cycle in the Drought Stress Responses of Wheat Roots

Abscisic acid(ABA),hydrogen peroxide(H_(2)O_(2)) and ascorbate(AsA)–glutathione(GSH)cycle are widely known for their participation in various stresses.However,the relationship between ABA and H_(2)O_(2) levels and the AsA–GSH cycle under drought stress in wheat has not been studied.In this study,a hydroponic experiment was conducted in wheat seedlings subjected to 15%polyethylene glycol(PEG)6000–induced dehydration.Drought stress caused the rapid accumulation of endogenous ABA and H_(2)O_(2) and significantly decreased the number of root tips compared with the control.The application of ABA significantly increased the number of root tips,whereas the application of H_(2)O_(2) markedly reduced the number of root tips,compared with that under 15%PEG-6000.In addition,drought stress markedly increased the DHA,GSH and GSSG levels,but decreased the AsA levels,AsA/DHA and GSH/GSSG ratios compared with those in the control.The activities of the four enzymes in the AsA–GSH cycle were also markedly increased under drought stress,including glutathione reductase(GR),ascorbate peroxidase(APX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR),compared with those in the control.However,the application of an ABA inhibitor significantly inhibited GR,DHAR and APX activities,whereas the application of an H_(2)O_(2) inhibitor significantly inhibited DHAR and MDHAR activities.Furthermore,the application of ABA inhibitor significantly promoted the increases of H_(2)O_(2) and the application of H_(2)O_(2) inhibitor significantly blocked the increases of ABA,compared with those under 15% PEG-6000.Taken together,the results indicated that ABA and H_(2)O_(2) probably interact under drought stress in wheat;and both of them can mediate drought stress by modulating the enzymes in AsA–GSH cycle,where ABA acts as the main regulator of GR,DHAR,and APX activities,and H_(2)O_(2) acts as the main regulator of DHAR and MDHAR activities.

盐胁迫和ABA处理下水稻基因组的可变剪接事件分析

基因的剪接方式在不同发育时期、不同组织以及不同外界环境条件下可以发生改变,即可变剪接。可变剪接在转录后水平上调控基因功能,增加基因功能的复杂性和多样性。目前已发现一些基因在环境因素刺激下会发生可变剪接,但是逆境下全基因组水平上的可变剪接事件在很多植物中还未完全了解,这些事件是否同时受到植物激素的调控目前也不清楚。为了了解水稻在外界逆境胁迫下的全基因组可变剪接事件,特别是脱落酸(ABA)信号途径被激活后哪些基因发生了可变剪接,我们对盐胁迫以及ABA处理后水稻转录组中的可变剪接事件进行了交叉分析,发现一些信号途径的基因在盐胁迫以及ABA处理后均发生了可变剪接。选择其中与DNA损伤修复以及ABA信号转导有关的基因进行了进一步分析,并通过RT-PCR对其中OsPP2C67和OsSADR1基因的可变剪接进行了验证,得到的结果与分析结果一致。

The CBL-interacting protein kinase OsCIPK1 phosphorylated by SAPK10 positively regulates responses to ABA and osmotic stress in rice

SubclassⅢsucrose nonfermenting1-related protein kinase 2s(SnRK2s)function in ABA and abiotic stress responses by unknown mechanisms.We found that osmotic stress/ABA-activated protein kinase 10(SAPK10),a member of rice SnRK2s,physically interacted with CBL-interacting protein kinase 1(OsCIPK1).OsCIPK1 expression was up-regulated by ABA and PEG treatment,and overexpression increased the ABA sensitivity of seed germination and root growth and plant osmotic stress tolerance.Osmotic stress or ABA-induced activation of OsCIPK1 is dependent on SAPK10.SAPK10 phosphorylates Thr-24 of OsCIPK1 in vitro,and this phosphorylation increases the activity of OsCIPK1 and positively regulates the function of OsCIPK1 in ABA responses and plant osmotic stress tolerance.This study suggests that OsCIPK1 is a direct phosphorylated substrate of SAPK10,and SAPK10-mediated phosphorylation of OsCIPK1 functions in ABA signaling and increases rice osmotic stress tolerance.

The ABA synthesis enzyme allele OsNCED2^(T)promotes dryland adaptation in upland rice

Upland rice shows dryland adaptation in the form of a deeper and denser root system and greater drought resistance than its counterpart,irrigated rice.Our previous study revealed a difference in the frequency of the OsNCED2 gene between upland and irrigated populations.A nonsynonymous mutation(C to T,from irrigated to upland rice)may have led to functional variation fixed by artificial selection,but the exact biological function in dryland adaptation is unclear.In this study,transgenic and association analysis indicated that the domesticated fixed mutation caused functional variation in OsNCED2,increasing ABA levels,root development,and drought tolerance in upland rice under dryland conditions.OsNCED2-overexpressing rice showed increased reactive oxygen species-scavenging abilities and transcription levels of many genes functioning in stress response and development that may regulate root development and drought tolerance.OsNCED2^(T)-NILs showed a denser root system and drought resistance,promoting the yield of rice under dryland conditions.OsNCED2^(T)may confer dryland adaptation in upland rice and may find use in breeding dryland-adapted,water-saving rice.

Zinc finger protein ZFP36 and pyruvate dehydrogenase kinase PDK1 function in ABA-mediated aluminum tolerance in rice

Aluminum(Al)toxicity poses a significant constraint on field crop yields in acid soils.Zinc finger protein36(ZFP36)is well-documented for its pivotal role in enhancing tolerance to both drought and oxidative stress in rice.This study unveils a novel function of ZFP36 modulated by abscisic acid(ABA)-dependent mechanisms,specifically aimed at alleviating Al toxicity in rice.Under Al stress,the expression of ZFP36significantly increased through an ABA-dependent pathway.Knocking down ZFP36 heightened Al sensitivity,while overexpressing ZFP36 conferred increased resistance to Al stress.Additionally,our investigations revealed a physical interaction between ZFP36 and pyruvate dehydrogenase kinase 1 in rice(OsPDK1).Biochemical assays further elucidated that OsPDK1 phosphorylates ZFP36 at the amino acid site 73–161.Subsequent experiments demonstrated that ZFP36 positively regulates the expression of ascorbate peroxidases(OsAPX1)and OsALS1 by binding to specific elements in their upstream segments in rice.Through genetic and phenotypic analyses,we unveiled that OsPDK1 influences ABA-triggered antioxidant defense to alleviate Al toxicity by interacting with ZFP36.In summary,our study underscores that pyruvate dehydrogenase kinase 1(OsPDK1)phosphorylates ZFP36 to modulate the activities of antioxidant enzymes via an ABA-dependent pathway,influencing tolerance of rice to soil Al toxicity.

外源ABA对盐胁迫下八棱海棠苗木生长及生理特性的影响

在盆栽条件下,设置空白对照(CK)、盐胁迫(N1)、盐胁迫+20 mg/L ABA(N2)、盐胁迫+35 mg/L ABA(N3)、盐胁迫+50 mg/L ABA(N4)共计5个处理,研究ABA对盐胁迫下八棱海棠苗木生长和生理特性的影响。结果表明,盐胁迫处理与对照相比显著降低了八棱海棠的株高、茎粗、净光合速率、总糖含量和氨基酸含量,提高了八棱海棠的SOD活性和POD活性。外源施加ABA提高了盐胁迫处理下八棱海棠的株高、茎粗、净光合速率、SOD活性、POD活性、总糖含量和氨基酸含量。综合比较来看,35 mg/L是外源ABA改善八棱海棠苗木生理特性并促进其生长的适宜浓度。

番茄品种耐寒性与ABA和可溶性糖含量的关系

以６个耐寒性不同的番茄品种为试材，经８、１２、１５和２５℃温度处理后，测定苗期和开花期ＡＢＡ、可溶性糖含量和呼吸强度。结果表明，随处理温度的降低，ＡＢＡ和可溶性糖的含量逐渐增加，低温下（８和１２℃）ＡＢＡ和可溶性糖的含量与品种的耐寒性呈显著或极显著正相关，且苗期和开花期表现一致。呼吸强度随处理温度的降低而下降，开花期高于苗期，但与番茄品种耐寒性相关性不明显。

外施6-BA和ABA提高玉米幼苗抗旱能力的作用及效果

用１０－５ｍｏｌ／Ｌ的６－ＢＡ或ＡＢＡ叶面喷施受旱玉米幼苗可减轻其干旱伤害。表现为叶片内超氧物歧化酶（ＳＯＤ）、过氧化物酶（ＰＯＤ）和过氧化氢酶（ＣＡＴ）活性下降受抑，过氧化作用产物丙二醛（ＭＤＡ）的增加减慢，同时水分胁迫条件下玉米幼苗光合速率的降低受抑。６－ＢＡ与ＡＢＡ相比，６－ＢＡ对保护酶活性下降的抑制效果明显大于ＡＢＡ，阻止ＭＤＡ累积的效果亦如此。６－ＢＡ和ＡＢＡ缓解旱害的作用机制可能与调节活性氧代谢有关。

拟南芥bZIP1转录因子通过与ABRE元件结合调节ABA信号传导

ABA作为一种重要的植物激素和生长调节剂,介导了高等植物在营养生长阶段对各种外界环境的响应和适应。bZIP类转录因子可以通过ABA依赖途径和ABA非依赖途径调节植物的生长发育和对非生物胁迫的耐性。本研究通过AtbZIP1T-DNA插入突变的拟南芥植株ko-1(SALK_059343)和ko-2(SALK_069489C)在ABA处理后的表型实验,验证了AtbZIP1参与ABA依赖的信号传导通路。采用"三引物法",分别在DNA水平和RNA水平通过PCR和RT-PCR验证了AtbZIP1基因在拟南芥突变体中的沉默效果。定量分析数据表明,在种子萌发阶段,经过0.6μmolL–1ABA和0.8μmolL–1ABA处理后,AtbZIP1缺失突变体拟南芥植株萌发率和叶片展开/绿色率比野生型植株高,在幼苗生长阶段,经过50μmolL–1ABA处理后,AtbZIP1缺失突变体拟南芥植株根长比野生型植株长。为了确定AtbZIP1基因参与ABA信号传导是否依赖于ABRE元件,在大肠杆菌中表达了AtbZIP1HIS6融合蛋白,并设计了核心序列为CACGTG的ABRE元件。凝胶阻滞电泳结果表明AtbZIP1融合蛋白可以与ABRE元件特异性结合。半定量RT-PCR分析表明,AtbZIP1基因的缺失改变了下游的ABA响应基因的表达。该结果表明,AtbZIP1可以通过与ABRE元件结合调节植物对ABA处理的敏感性和下游ABA响应基因的表达,从而参与植物的ABA信号传导通路。

HPLC法检测果实组织中内源IAA、ABA方法的改进

以柑橘、猕猴桃、桃和葡萄果实为材料,在前人研究的基础上,结合近10年的研究积累,针对果实组织材料富含多酚类和色素等杂质的特点,对以往的HPLC分析植物内源激素的植物材料前处理方法进行了改进,并配合适宜的HPLC色谱条件,用于果实组织内源IAA和ABA的分析测定。结果显示该改进方法适合果实组织内源IAA和ABA的分析测定。

PEG胁迫下小麦幼苗ABA与Ca^(2+)/CaM的关系

本文以不同浓度钙离子螯合剂 EGTA、钙通道阻断剂异博啶 (Vp)和 Ca M拮抗剂三氟啦嗪 (TFP)处理小麦幼苗 ,对 PEG胁迫下根和叶片 ABA和 Ca M含量的变化进行了测定。结果表明 :EGTA、Vp和 TFP处理皆能促进根和叶片 ABA含量的提高。PEG胁迫下不同浓度 EGTA和 Vp处理后 Ca M含量也不同程度地提高 ,TFP处理可减弱PEG对 Ca M含量升高的促进作用。从 ABA和 Ca M最大峰值出现的时间上看 ,Ca M都滞后于 ABA。上述结果暗示 :Ca2 + / Ca M可能参与干旱信号 ABA的信息传递过程 ,而 ABA合成过程与胞质 Ca2 + 浓度有关。

Picloram,ABA和TDZ对香蕉体细胞胚胎发生的影响

研究Picloram、ABA和TDZ对贡蕉未成熟花序来源的胚性细胞悬浮系体细胞胚胎发生的影响。结果表明,8.28μmol/L Picloram替代2,4-D可获得15.56%的胚性愈伤组织诱导率;在体细胞胚诱导初期加入ABA则抑制体细胞胚的发生,并造成其萌发时严重愈伤化;TDZ可有效地改善体胚萌发率和植株转换率,其中0.2μmol/L TDZ处理的体胚萌发率和植株转换率分别从对照的17.28%、16.49%提高到72.77%和67.05%。

外源ABA对寒地冬小麦东农冬麦1号幼苗生长及抗冷性的影响

为给高寒地区冬小麦返青率的提高提供依据，以抗寒品种东农冬麦1号为试验材料，在添加ABA（浓度分别为0、10^-4、10^-5、10^-6、10^-7mol/L）的琼脂（3%）培养基上暗培养（温度2-4℃，培养盒倾斜45°角），第11天分别调查胚芽和根系生长状况，研究了外源ABA对冬小麦幼苗生长及抗冷性的影响。结果表明，外源ABA对小麦的抗冷性有很大影响，低浓度的ABA可以促进低温下小麦的生长，提高其抗冷性，而高浓度则抑制生长。ABA提高小麦抗冷性的最适浓度为10^-7mol/L。苗期低温下，ABA可以提高叶绿素含量、可溶性糖含量、可溶性蛋白含量，增加SOD活性，降低膜透性。根浸ABA对提高幼苗抗冷效果要强于叶喷ABA。

ABA对水稻愈伤组织、不定胚发育及其植株再生的影响

以长期培养的水稻愈伤组织为材料,用不同浓度的ABA对其进行了前处理,对愈伤组织的结构变化、植株再分化率、不定胚和器官分化的形成进行了研究。结果表明,经10 mg/L ABA前处理的愈伤组织外缘部分表现出禾本科类不定胚形成前期的形态结构,10 mg/L ABA预处理不仅能使分化时间缩短1周,而且使植株再生率明显提高,说明ABA对细胞再分化进程有明显的促进作用。