<p>PHYTOCHROME INTERACTING FACTOR 4 (PIF4) is known as a basic helix-loop-helix (bHLH) transcription factor that interacts with phytochrome and is integral to the Phytochrome B (phyB)-mediated regulation of seedling de-etiolation and photomorphogenesis, primarily by modulating cell expansion. Previous research has indicated that auxin might exacerbate pathogen-induced diseases by suppressing salicylic acid (SA)-dependent host defense mechanisms or through pathways independent of SA. This study was conducted to elucidate the function of PIF4 in orchestrating plant growth and innate immunity. Experiments with a PIF4 loss-of-function mutant revealed heightened immune defense against type III secretion system (T3SS) deficient bacteria <i>Pseudomonas syringae pv. tomato</i> (<i>Pto hrcC</i><sup><i>−</i></sup>), suggesting that PIF4 suppresses immunity. Upon pathogen detection, PIF4 upregulated the expression of indole acetic acid (IAA) biosynthesis-related genes, thereby promoting plant growth, while concurrently downregulating genes essential for SA biosynthesis, which are critical for PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Furthermore, PIF4 attenuated flg22-induced reactive oxygen species (ROS) production and callose accumulation. Moreover, the hypersensitive response and ROS production induced by <i>Pto</i> effectors <i>AvrRpm1</i> and <i>AvrRpt2</i> were diminished in the <i>pif4-1</i> mutant, reinforcing the notion that PIF4 negatively influences ETI. Therefore, these findings revealed that PIF4 exhibited a negative function in plant innate defense signaling during dynamic interactions between <i>Arabidopsis</i> and <i>Pseudomonas</i>.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

PIF4 Negatively Regulates Plant Defense Against Pseudomonas syringae via Suppression of PAMP- and Effector-Triggered Immunity

  • Donah Mary Macoy,
  • Shahab Uddin,
  • Kris John Silvano,
  • Gyeong Ryul Ryu,
  • Hamad Khan,
  • Rakhimov Abdurakhim Ramazon Ugli,
  • Gyeongik Ahn,
  • Joon-Yung Cha,
  • Woe-Yeon Kim,
  • Min Gab Kim

摘要

PHYTOCHROME INTERACTING FACTOR 4 (PIF4) is known as a basic helix-loop-helix (bHLH) transcription factor that interacts with phytochrome and is integral to the Phytochrome B (phyB)-mediated regulation of seedling de-etiolation and photomorphogenesis, primarily by modulating cell expansion. Previous research has indicated that auxin might exacerbate pathogen-induced diseases by suppressing salicylic acid (SA)-dependent host defense mechanisms or through pathways independent of SA. This study was conducted to elucidate the function of PIF4 in orchestrating plant growth and innate immunity. Experiments with a PIF4 loss-of-function mutant revealed heightened immune defense against type III secretion system (T3SS) deficient bacteria Pseudomonas syringae pv. tomato (Pto hrcC), suggesting that PIF4 suppresses immunity. Upon pathogen detection, PIF4 upregulated the expression of indole acetic acid (IAA) biosynthesis-related genes, thereby promoting plant growth, while concurrently downregulating genes essential for SA biosynthesis, which are critical for PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Furthermore, PIF4 attenuated flg22-induced reactive oxygen species (ROS) production and callose accumulation. Moreover, the hypersensitive response and ROS production induced by Pto effectors AvrRpm1 and AvrRpt2 were diminished in the pif4-1 mutant, reinforcing the notion that PIF4 negatively influences ETI. Therefore, these findings revealed that PIF4 exhibited a negative function in plant innate defense signaling during dynamic interactions between Arabidopsis and Pseudomonas.