茉莉酸信号转导突变体ber15 的分离和基因克隆表明油菜素内酯的合成影响茉莉酸信号转导

bestatin是一种氨肽酶抑制剂, 能够激活茉莉酸信号转导途径而诱导抗性相关基因的表达, 从而为用化学遗传学手段解析茉莉酸途径提供了一个有效的工具。ber15是我们鉴定到的一个对bestatin不敏感的拟南芥突变体, 随后的研究表明该突变体对外源茉莉酸的敏感性也明显降低, 表明相应的野生型基因BER15在茉莉酸信号转导中起重要作用。图位克隆结果表明BER15编码一个细胞色素P450单加氧酶, 是植物激素油菜素内酯合成途径中的一个关键酶。对BER15基因功能的深入研究将会为了解油菜素内酯的合成与茉莉酸信号途径间的互作关系提供证据。     

茉莉酸信号转导突变体ber15的分离和基因克隆表明油菜素内酯的合成影响茉莉酸信号转导

bestatin是一种氨肽酶抑制剂,能够激活茉莉酸信号转导途径而诱导抗性相关基因的表达,从而为用化学遗传学手段解析茉莉酸途径提供了一个有效的工具。ber15是我们鉴定到的一个对bestatin不敏感的拟南芥突变体,随后的研究表明该突变体对外源茉莉酸的敏感性也明显降低,表明相应的野生型基因BER15在茉莉酸信号转导中起重要作用。图位克隆结果表明BER15编码一个细胞色素P450单加氧酶,是植物激素油菜素内酯合成途径中的一个关键酶。对BER15基因功能的深入研究将会为了解油菜素内酯的合成与茉莉酸信号途径间的互作关系提供证据。     

Changes in Oil Accumulation and Fatty Acid Composition of Soybean Seeds under Salt Stress in Response to Salicylic Acid and Jasmonic Acid

greenhouse experiment with factorial arrangement based on randomized complete block design with four replications was conducted in 2015 to evaluate the effects of salicylic acid (SA) (1 mM) and jasmonic acid (JA) (0.5 mM) on oil accumulation and fatty acid composition of soybean oil (Glycine max L.) under salt stress (Non-saline, 4, 7, and 10 dS/m NaCl). Oil percentage of soybean seeds declined, while oil content per seed enhanced with increasing seed filling duration. Foliar application of SA improved oil content per soybean seed at different stages of development under all salinity levels. Although JA treatment enhanced seed oil percentage, oil yield of these plants decreased as a result of reduction in seed yield per plant. In contrast, the highest oil yield was recorded for SA treated plants, due to higher seed yield. Salinity had no significant effects on percentage of palmitic acid and stearic acid, but treatment with JA significantly reduced stearic acid percentage. Oleic acid content of seeds increased, but percentages of linoleic acid, linolenic acid and unsaturation index (UI) of soybean oil decreased with increasing salinity. Foliar application of SA and JA improved oil quality of soybean seeds by reducing oleic acid and enhancing linoleic acid, linolenic acid contents and UI. Exogenous application of SA had the most beneficial effects on soybean seeds due to enhancing oil yield and quality under saline and non-saline conditions.     

葡萄幼苗在温度胁迫交叉适应过程中对水杨酸的应答

在温度锻炼诱导葡萄幼苗对交叉温度逆境的适应过程中叶片内源SA变化的结果表明,0℃低温胁迫期间,葡萄幼苗叶片细胞膜系统受到严重伤害,丙二醛(MDA)含量明显升高;此时自由态SA含量呈波动性变化,并随着胁迫进程的延长,内源SA含量明显低于正常叶片水平。而经过高温锻炼的幼苗,在低温胁迫初期自由态SA含量迅速达到一个高峰,之后回落并保持在正常叶片的SA水平,MDA含量也相应降低且相对稳定。结合态SA的变化相对较平稳,并且总SA含量变化趋势与自由态SA含量的变化趋势相吻合。在45℃高温胁迫期间,经过低温锻炼的幼苗的上述各项指标的变化规律与经过高温锻炼的幼苗在低温胁迫期间的变化趋势相似。     

激发子α-吡啶羧酸诱发拟南芥和水稻悬浮细胞中依赖于水杨酸、茉莉酸/乙烯和钙离子途径的防卫反应

α-吡啶羧酸(PA)是动物细胞程序化死亡的诱导物.我们前期的研究表明,PA可以激发单子叶模式植物水稻的过敏反应(HR).进一步用双子叶模式植物拟南芥(Arabidopsis thaliana)进行的研究表明,PA是一个广谱的植物HR反应的激发子,包括诱导氧进发和细胞死亡.我们探究了PA诱导的拟南芥防卫反应途径,利用不同信号途径标志基因PR-1,PR-2和PDF1.2受诱导剂量和时间激活的结果,表明PA可以同时激活水杨酸和茉莉酸/乙烯依赖的防卫途径.我们也发现PA诱导水稻悬浮细胞产生活性氧是钙离子依赖性的.综合所有结果,我们认为PA可以作为一个非专化性的植物防卫反应激发子,可望用于系统获得性抗性激发的细胞模型的建立.     

激发子α-吡啶羧酸诱发拟南芥和水稻悬浮细胞中依赖于水杨酸、茉莉酸/乙烯和钙离子途径的防卫反应(英文)

α-吡啶羧酸(PA)是动物细胞程序化死亡的诱导物。我们前期的研究表明,PA可以激发单子叶模式植物水稻的过敏反应(HR)。进一步用双子叶模式植物拟南芥(Arabidopsis thaliana)进行的研究表明,PA是一个广谱的植物HR反应的激发子,包括诱导氧进发和细胞死亡。我们探究了PA诱导的拟南芥防卫反应途径,利用不同信号途径标志基因PR-1,PR-2和PDF1.2受诱导剂量和时间激活的结果,表明PA可以同时激活水杨酸和茉莉酸/乙烯依赖的防卫途径。我们也发现PA诱导水稻悬浮细胞产生活性氧是钙离子依赖性的。综合所有结果,我们认为PA可以作为一个非专化性的植物防卫反应激发子,可望用于系统获得性抗性激发的细胞模型的建立。     

Biochemical and Physiological Response to Salicylic Acid in Relation to the Systemic Acquired Resistance

In five genotypes of cowpea (Vigna unguiculata), the influence of salicylic acid (SA) on photosynthetic activity and biochemical constituents including peroxidase activity at the genotypic level was determined. After SA treatment the total free sugar content increased in IFC 8401 and IGFRI 450 genotypes, whereas the content of total leaf soluble proteins decreased significantly in IFC 902. The high chlorophyll (Chl) (a + b) content in IFC 902 showed a good correlation with the net photosynthetic rate (PN), as in this genotype a significant increase in PN was found after the SA treatment.     

PIF4 and PIF5 Transcription Factors Link Blue Light and Auxin to Regulate the Phototropic Response in Arabidopsis

Both blue light (BL) and auxin are essential for phototropism in Arabidopsis thaliana. However, the mechanisms by which light is molecularly linked to auxin during phototropism remain elusive. Here, we report that PHYTOCHROME INTERACTING FACTOR4 (PIF4) and PIF5 act downstream of the BL sensor PHOTOTROPIN1 (PHOT1) to negatively modulate phototropism in Arabidopsis. We also reveal that PIF4 and PIF5 negatively regulate auxin signaling. Furthermore, we demonstrate that PIF4 directly activates the expression of the AUXIN/INDOLE-3-ACETIC ACID (IAA) genes IAA19 and IAA29 by binding to the G-box (CACGTG) motifs in their promoters. Our genetic assays demonstrate that IAA19 and IAA29, which physically interact with AUXIN RESPONSE FACTOR7 (ARF7), are sufficient for PIF4 to negatively regulate auxin signaling and phototropism. This study identifies a key step of phototropic signaling in Arabidopsis by showing that PIF4 and PIF5 link light and auxin.     

水杨酸、茉莉酸和乙烯在调控蚕豆气L运动中的相互关系

以蚕豆下表皮为材料研究了水杨酸、(±)茉莉酸和乙烯对气孔运动的影响及其相互关系。结果表明,在一定范围内,水杨酸和乙烯利都可诱导气孔关闭,并且二者能够相互增强其作用强度;(±)茉莉酸能够促进气孔开度增大,加入(±)茉莉酸减弱了乙烯利对气孔运动的影响,(±)茉莉酸和乙烯利存在拮抗效应。降低内源乙烯的水平可以增强(±)茉莉酸促进气孔张开的作用、降低水杨酸的诱导气孔关闭效应。而水杨酸和(±)茉莉酸之间的关系比较复杂。     

Jasmonic Acid is Induced in a Biphasic Manner in Response of Pea Seedlings to Wounding

The role of jasmonic acid (JA) in plant wounding response has been demonstrated. However, the source of JA in wound signaling remains unclear. In the present study, pea seedlings were used as material to investigate the systemic induction of JA and the activation of lipoxygenase (LOX)-dependent octadecanoid pathway upon wounding. The results showed that endogenous JA could induce two peaks in the wounded leaves and the stalks, while only one peak in the systemic leaves.LOX activity and its protein amount were also induced and the stimulation mainly occurred in the late phase, while one peak of induction was present after pretreatment with JA. Applied nordihydroguaiaretic acid (NDGA), an inhibitor of LOX activity, only inhibited the induction of JA in the late phase, and the resistance of pea was impaired. Furthermore, 13(S)-hydroperoxy-9(Z), 11 (E)-octadecadienoic acid (13(S)-H(P)ODE) was confirmed to be the main product of LOX throughout the experimental time. In addition, immunocytochemical analysis also revealed the occurrence of JA biosynthesis and transport upon wounding. These results demonstrated that wound-induced JA in wounded leaves resulted from Its biosynthesis and conversion from its conjugates, while in systemic leaves resulted from its transport and biosynthesis; and proved that the LOX pathway was vital to the wound-induced defense response involved in JA biosynthesis.     

Jasmonic Acid is Induced in a Biphasic Manner in Response of Pea Seedlings to Wounding

The role of jasmonic acid （JA） in plant wounding response has been demonstrated. However, the source of JA in wound signaling remains unclear. In the present study, pea seedlings were used as material to investigate the systemic induction of JA and the activation of lipoxygenase （LOX）-dependent octadecanoid pathway upon wounding. The results showed that endogenous JA could induce two peaks in the wounded leaves and the stalks, while only one peak in the systemic leaves. LOX activity and its protein amount were also induced and the stimulation mainly occurred in the late phase, while one peak of induction was present after pretreatment with JA. Applied nordihydroguaiaretic acid （NDGA）, an inhibitor of LOX activity, only inhibited the induction of JA in the late phase, and the resistance of pea was impaired. Furthermore, 13（S）- hydroperoxy-9（Z）, 11 （E）-octadecadienoic acid （13（S）-H（P）ODE） was confirmed to be the main product of LOX throughout the experimental time. in addition, immunocytochemical analysis also revealed the occurrence of JA biosynthesis and transport upon wounding. These results demonstrated that wound-induced JA in wounded leaves resulted from its biosynthesis and conversion from its conjugates, while in systemic leaves resulted from its transport and biosynthesis; and proved that the LOX pathway was vital to the wound-induced defense response involved in JA biosynthesis.