Nitric oxide involved in signal transduction of Jasmonic acid-induced stomatal closure of Vicia faba L.

Nitric oxide (NO) and Jasmonic acid (JA) are two key signaling molecules involved in many and diverse biological pathways in plants. Growing evidence suggested that NO signaling interacts with JA signaling. In this work, Our experiment showed that NO exists in guard cell of Vicia faba L., and NO is involved in signal transduction of JAinduced stomata closuring: ( i ) JA enhances NO synthesis in guard cell; ( ii ) both JA and NO induced stomatal closure, and had dose response to their effects; ( iU ) there are synergetic correlation between JA and lower NO concentration in regulation of stomatal movement; (iV) JA-induced stomatal closure was largely prevented by 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (PTIO), a specific NO scavenger. An inhibitor of NO synthase (NOS) in mammalian cells, N^G-nitro-L-Arg-methyl eater (L-NAME) also inhibits plant NOS, repressing JA-induced NO generation and JA-induced stomatal closure. We presumed that NO mainly comes from NOS after JA treatment.     

Involvement of nitric oxide in the signal transduction of salicylic acid regulating stomatal movement

The effects and the relationship between sali-cylic acid(SA)and nitric oxide(NO) on Vicia faba L.stomatal movement were studied.The results here showed that exogenous SA and NO induced stomatal closure,100μmol/L SA induced a rapid and striking NO increase in the cytosol of guard cells.This phenomenon was largely prevented by 2000μmol/L 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide(PTIO),a specific NO scavenger,and 25μmol/L N^G-nitro-L-Arg-methyl eater (L-NAME),an inhibitor of NO synthase(NOS) in mammalian cells that also inhibits plant NOS.In addition,SA-induced stomatal closure was largely prevented by PTIO and L-NAME.These results provide evidence that guard cells generate NO in response to SA via NOS-like activity,and that such NO production is required for full stomatal closure in response to SA.H-(1,2,4)-oxadiazole-[4,3-α]quinoxalin-l-one(ODQ),an inhibitor of guanylate cyclase,and nicotinamide,an antagonist of cADPR production,inhibited the effects of SA-and NO-induced stomatal closure.It suggests that both cGMP and cADPR might mediate the signal transduction of SA and NO-induced stomatal closure.     

Ca^2＋ is involved in muscarine-acetylcholine-receptor-mediated acetylcholine signal transduction in guard cells of Vicia faba L.

Acetyicholine (ACh) is an important neuro-chemical transmitter in animals; it also exists in plants and plays a significant role in various kinds of physiological functions in plants. ACh has been known to induce the stomatal opening. By monitoring the changes of cytusolic Ca^2 with fluorescent probe Fiuo-3 AM under the confocal microscopy, we found that exogenous ACh increased cytosolic Ca^2 concentration of guard cells of Vicia faba L. Muscarlne, an agonist of muscarine acetyicholine receptor (mAChR), could do so as well. In contrast, atropine, the antagonist of mAChR abolished the ability of ACh to increase Ca^2 in guard cells. This mechanism is similar to mAChR in animals. When EGTA was used to chelate Ca^2 or ruthenium red to block Ca^2 released from vacuole respectively, the results showed that the increased cytosolic Ca^2 mainly come from intracellular Ca^2 store. The evidence supports that Ca^2 is involved in guard-cell response to ACh and that Ca^2 sigual is coupled to mAChRs in ACh signal transduction in guard cells.     

植物抗病性的分子机制和信号传导

植物抗病性的分子机制一直是植物病理学关注的焦点.近年来,国内外不少学者和实验室正在大量分离和培养与抗病有关的突变体,并且寻找和研究与抗病有关的基因和抗病机制.研究表明,在病原物与植物的相互作用、病原信号的传导和抗病性激发的过程中存在着一系列的调节因子和基因,并形成复杂的调控网络.综述了近年来国内外植物抗病性的分子研究进展,阐述了植物抗病性分子机制和信号传导.     

植物在渗透胁迫下信号转导的级联机制

研究植物在渗透胁迫下信号转导的级联机制,对于有效调控植物在逆境中的生长发育,提高其抗逆性和生存能力具有重要的指导意义．根据近年来国内外的研究成果和报道,综述了植物细胞在渗透胁迫下感受到信号后,相继产生许多信号分子,这些信号分子通过细胞壁-质膜-细胞骨架连续体,引起细胞骨架蛋白变构而传递信息,并与细胞膜蛋白、第二信使系统以及调节因子构成了信号传递网,最终有条不紊地引起特定的基因表达和应答．     

Involvement of Ca<Superscript>2+</Superscript>/CaM in the signal transduction of acetylcholine regulating stomatal movement

It has been known that the neurotransmitter acetylcholine (ACh) also exists in plants and is able to regulate the movement of stomata.In another aspect,Ca^2 /CaM as the second messengers have a critical role of signal transduction in stomatal guard-cell,Here we showed that Ca^2 /CaM were also involved in the ACh regulated stomatal movement,In the medium containing Ca^2 ,the Ca^2 channel blockers (NIF and Ver)and CaM inhibitors (TFP and W7 ) could neutralize the ACh induced stomatal opening,however,they are ineffective in the medium containing K^ ,Those results indicated that Ca^2 /CaM were involved in the signal transduction pathway of ACh regulating stomatal movement.     

蛋白激酶与植物渗透胁迫耐受研究进展

蛋白激酶是一类能使其他蛋白质磷酸化的酶.在植物中,蛋白激酶几乎参与植物生命周期中一切生理调节过程.渗透胁迫是植物生长发育过程中常见的非生物胁迫,植物对渗透胁迫耐受的机理一直是研究的重点.本文着眼于植物渗透胁迫反应,详细介绍了分裂原激活蛋白激酶(MAPK)、钙依赖而钙调素不依赖的蛋白激酶(CDPK)、受体蛋白激酶(RPK)、核糖体蛋白激酶、转录调控蛋白激酶等多种蛋白激酶在植物逆境信号识别与转导中的作用,综述其研究进展及前景.分析了当前在植物抗渗透胁迫蛋白激酶研究中存在的问题,进而对解决问题的途径进行了探讨.     

蚕豆(Vicia faba L.)对不同水分胁迫的光合适应性研究

以重庆市的蚕豆当家品种之一的大白豆为材料,通过人工水分胁迫处理,发现随干旱程度的增加,蚕豆叶片的叶绿素a、叶绿素b含量和叶绿素总降低,Hill反应活力下降,净光合速率下降,同化产物的积累减少,最终表现为植株生物量的降低,水分胁迫下植株净光合速率下降,光饱和点降低,光补偿点提高,CO2补偿点提高,光呼吸增大,生长减弱,这时导致生物量积累减少的主要原因。     

Cytokinin signal transduction： Known simplicity and unknown complexity

Cytokinin plays a critical role in plant growth and development by regulating cell divisions and cell differentiation. Recent studies suggest that cytokinin signaling is presumably mediated by a two-component system analogous to those found in bacteria and fungi, which transduces an external signal via a phosphorelay from the plasma membrane-anchored receptors to downstream effectors and regulators. Moreover, cytokinin signaling is highly interactive with other pathways, and many components of the pathway appear to be functionally redundant. Proper address of these questions will be crucial for our further understanding on this important network.     

Brassinosteroid signal transduction: An emerging picture

Brassinosteroids (BRs) are plant steroid hormones that have similar structures and functions with Brassino-lide (BL). BR signaling is complicated, and the input of BR signal is under fine control. The active BR level is regulated at the levels of BR biosynthesis and metabolic inactivation[1,2]. BR biosynthetic pathway consists of a metabolic grid, and the expression of several genes for BR biosynthesis is feedback regulated by BR signaling[3,4]. The sequential events of BR action inclu…     

脱落酸对镉胁迫下蚕豆幼苗光合参数和抗氧化酶的影响

通过外用ABA(25μmol/L)对镉胁迫下蚕豆幼苗光合参数及抗氧化酶活性变化进行测定分析.结果表明,在无ABA情况下,10 mg/L的镉胁迫能够使蚕豆叶片的光合速率(Pn),蒸腾速率(Tr),气孔导度(Gs)和胞间CO2浓度(Ci)呈上升趋势,随着浓度的增加,各参数逐渐降低.当外用ABA后,除蒸腾速率外,其余各参数的降低趋势被明显抑制.此外,外用ABA还可以减少在镉胁迫下蚕豆叶片MDA含量和膜透性的增加值,提高蚕豆叶片抗氧化酶(CAT,SOD,POD)活性.     

水分胁迫对蚕豆（Vicia faba L.）光合作用及产量的影响

以重庆市的蚕豆当家品种香珠豆为材料,通过人工水分胁迫处理,发现随土壤干旱程度的增加,蚕豆叶片的净光合速度下降,光饱和点降低,光补偿点提高,CO2补偿点提高,光呼吸增大;生长减弱,同化产物的积累减少,最终表现为植株的株高、根长、鲜干重、叶面积、根瘤的数量与重量、开花数、结荚数都明显下降,根冠比则上升。这是导致生物量积累减少的主要原因。     

叶面施硼对蚕豆生物效应的影响

用不同浓度的硼酸溶液在蚕豆不同生长期进行叶面喷施.结果表明,在蚕豆生长的幼苗期、现蕾期和开花期叶面喷施0.1%-0.2%的硼酸溶液能促进蚕豆的生长和产量的增加.可能施硼后导致蚕豆叶片的SOD活性和CAT活性的增强,同时降低了O2-生成速率和MDA含量.     

Protein tyrosine phosphatases involved in signaling of the ABA-induced H2O2 generation in guard cells of Vicia faba L.

Although protein tyrosine phosphatases (PTPases) play an important role in signal transduction in animal cells, little is known about the function of PTPases in higher plants. Hydrogen peroxide (H2O2) and mitogen-activated protein kinases (MAPKs) are the critical components of ABA signaling pathway in guard cells. PTPase is an important regulator of MAPK, which is believed to mediate ABA-induced H2O2 generation in guard cells of Vicia faba L. Here, we investigate the possible role of PTPases in stomatal movement process. Phenylarsine oxide (PAO), a specific inhibitor of PTPases, could prevent ABA or H2O2-induced stomatal closure of Vicia faba L; furthermore, it could promote opening of the stomata closed by ABA or H2O2. The activity of PTPases can be effectively inhibited by PAO and H2O2. DTT had no effect on the PAO-induced inhibition of PTPases activity, but it could relieve the inhibition of H2O2 on PTPases activity. PAO could also inhibit the ABA-induced H2O2 generation in guard cells of V‘wia faba L. These results suggested that PTPases is a critical signaling component in ABA-induced stomatal closure, and serve as targets for H2O2 lying on the signaling pathways downstream of ABA induced H2O2 generation.     

Na2CO3胁迫对蚕豆幼苗几种生理生化指标的影响

用Na2CO3处理蚕豆幼苗,处理浓度为25,50,75,100mmol／L,胁迫6天后取样,测定植株鲜干重、肉质化程度、细胞膜透性、丙二醛含量、脯氨酸含量叶绿素含量等生理指标．结果表明,一定浓度的Na2CO3促进了蚕豆幼苗鲜干重、肉质化程度、叶绿素含量的增加,100mmol／LNa2CO3处理明显抑制了蚕豆幼苗的生长．Na2CO3浓度超过75mmol／L时,蚕豆幼苗MDA含量急剧上升,质膜透性也明显增加,脯氨酸含量增加明显．     

一氧化氮的细胞内信号转导

本文从一氧化氮/环鸟苷酸途径;激活环氧化酶;调节蛋白激酶C;影响转录因子等多个方面对一氧化氮(NO)的细胞内信号转导途径进行了阐述.     

春蚕豆试管苗炼苗和移栽技术研究

通过对春蚕豆试管苗炼苗方法与移栽技术的研究，总结出一套蚕豆试管苗炼苗移栽的工艺流程；采用闭口一开口炼苗方法后，试管苗长势好，抗性强，成苗率达90％以上。     

蓝藻真核型蛋白质激酶与信号传导

对最近10年在蓝藻中找到大量编码Ser／Thr基因的研究结果进行了综述,并对这些蛋白质激酶在信号传导中的作用模式做了讨论．     

Localization of muscarinic acetylcholine receptor in plant guard cells

Acetylcholine (ACh), as an important neurotransmitter in animals, also plays a significant role in various kinds of physiological functions in plants. But relatively little is known about its receptors in plants. A green fluorescence BODIPY FL-labeled ABT, which is a high affinity ligand of muscarinic acetylcholine receptor (mAChR), was used to localize mAChR in plant guard cells. InVicia faba L. andPisum sativum L., mAChR was found both on the plasma membrane of guard cells. mAChR may also be distributed on guard cell chloroplast membrane ofVicia faba L. The evidence that mAChR localizes in the guard cells provides a new possible signal transduction pathway in ACh mediated stomata movement.