PDF(Pubmed)
Abstract：
In wounded Arabidopsis thaliana leaves, four 13S-lipoxygenases (AtLOX2, AtLOX3, AtLOX4, AtLOX6) act in a hierarchical manner to contribute to the jasmonate burst. This leads to defense responses with LOX2 playing an important role in plant resistance against caterpillar herb-ivory. In this study, we sought to characterize the impact of AtLOX2 on wound-induced phytohormonal and transcriptional responses to foliar mechanical damage using wildtype (WT) and lox2 mutant plants. Compared with WT, the lox2 mutant had higher constitutive levels of the phytohormone salicylic acid (SA) and enhanced expression of SA-responsive genes. This suggests that AtLOX2 may be involved in the biosynthesis of jasmonates that are involved in the antagonism of SA biosynthesis. As expected, the jasmonate burst in response to wounding was dampened in lox2 plants. Generally, 1 h after wounding, genes linked to jasmonate biosynthesis, jasmonate signaling attenuation and abscisic acid-responsive genes, which are primarily involved in wound sealing and healing, were differentially regulated between WT and lox2 mutants. Twelve h after wounding, WT plants showed stronger expression of genes associated with plant protection against insect herbivory. This study highlights the dynamic nature of jasmonate-responsive gene expression and the contribution of AtLOX2 to this pathway and plant resistance against insects.
摘要：
在受伤的拟南芥叶子中，四种13S-脂氧合酶（AtLOX2，AtLOX3，AtLOX4，AtLOX6）以分层方式起作用以促进茉莉酸爆发。这导致L0X2在植物对毛虫草本植物象牙的抗性中起重要作用的防御反应。在这项研究中,我们试图使用野生型（WT）和lox2突变植物表征AtLOX2对伤口诱导的植物激素和对叶面机械损伤的转录反应的影响。与WT相比,lox2突变体具有较高的植物激素水杨酸（SA）组成水平，并增强了SA响应基因的表达。这表明AtLOX2可能参与茉莉酸的生物合成，而茉莉酸与SA生物合成的拮抗作用有关。不出所料,在lox2植物中，响应受伤的茉莉酸爆发被抑制。一般来说,受伤后1小时，与茉莉酸生物合成相关的基因，茉莉酸信号衰减和脱落酸响应基因，主要参与伤口的封闭和愈合，WT和lox2突变体之间的差异调节。受伤后十二小时，WT植物显示出与植物针对昆虫草食动物的保护相关的基因的更强表达。这项研究强调了茉莉酸响应基因表达的动态性质以及AtLOX2对该途径和植物对昆虫的抗性的贡献。
