Sarowar Sujon, Kim Young Jin, Kim Ki Deok, Hwang Byung Kook, Ok Sung Han, Shin Jeong Sheop
School of Life Sciences and Biotechnology, Korea University, Seoul, South Korea.
Plant Cell Rep. 2009 Mar;28(3):419-27. doi: 10.1007/s00299-008-0653-3. Epub 2008 Dec 16.
The lipid signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. To investigate the biological functions of pepper lipid transfer protein (LTP), we carried out virus-induced gene silencing (VIGS) in pepper, constitutive expression of CALTPs and grafting experiments in the tobacco plant. Suppression of endogenous CALTPI and CALTPII by VIGS, respectively, resulted in enhanced susceptibility to Xanthomonas campestris pv. vescatoria and pepper mosaic mottle virus in pepper. On the other hand, the constitutive expression of CALTPI and CALTPII genes in tobacco plants showed enhanced resistance to oomycete pathogen, Phytophthora nicotianae and bacterial pathogen, Pseudomonas syringae pv. tabaci. Enhanced resistance is found to be associated with the enhanced CALTP transcript levels in the independent transgenic CALTPI or II tobacco lines. Induced resistance responses in grafted scion leaves revealed that LTP plays a role in long-distance systemic signaling in plants.
脂质信号对于激活植物防御反应至关重要，但该信号通路的下游组分仍未明确界定。为了研究辣椒脂质转移蛋白（LTP）的生物学功能，我们在辣椒中进行了病毒诱导的基因沉默（VIGS），在烟草植株中进行了CALTPs的组成型表达和嫁接实验。通过VIGS分别抑制内源性CALTPI和CALTPII，导致辣椒对野油菜黄单胞菌疮痂致病变种和辣椒花叶斑驳病毒的易感性增强。另一方面，烟草植株中CALTPI和CALTPII基因的组成型表达显示出对卵菌病原体烟草疫霉和细菌病原体丁香假单胞菌烟草致病变种的抗性增强。在独立的转基因CALTPI或II烟草品系中，发现增强的抗性与增强的CALTP转录水平相关。嫁接接穗叶片中的诱导抗性反应表明，LTP在植物的长距离系统信号传导中发挥作用。
