Gnanasekaran Prabu, Zhai Ying, Kamal Hira, Smertenko Andrei, Pappu Hanu R
Department of Plant Pathology, Washington State University, Pullman, WA, United States.
Institute of Biological Chemistry, Washington State University, Pullman, WA, United States.
Front Plant Sci. 2023 Sep 11;14:1112821. doi: 10.3389/fpls.2023.1112821. eCollection 2023.
Potato virus Y (PVY) is an economically important plant pathogen that reduces the productivity of several host plants. To develop PVY-resistant cultivars, it is essential to identify the plant-PVY interactome and decipher the biological significance of those molecular interactions. We performed a yeast two-hybrid (Y2H) screen of cDNA library using PVY-encoded NIa-pro as the bait. The (IAAS) was identified as an interactor of NIa-pro protein. The interaction was confirmed via targeted Y2H and bimolecular fluorescence complementation (BiFC) assays. NIa-pro interacts with IAAS protein and consequently increasing the stability of IAAS protein. Also, the subcellular localization of both NIa-pro and IAAS protein in the nucleus and cytosol was demonstrated. By converting free IAA (active form) to conjugated IAA (inactive form), IAAS plays a crucial regulatory role in auxin signaling. Transient silencing of IAAS in plants reduced the PVY-mediated symptom induction and virus accumulation. Conversely, overexpression of IAAS enhanced symptom induction and virus accumulation in infected plants. In addition, the expression of auxin-responsive genes was found to be downregulated during PVY infection. Our findings demonstrate that PVY NIa-pro protein potentially promotes disease development via modulating auxin homeostasis.
马铃薯Y病毒（PVY）是一种具有重要经济意义的植物病原体，会降低多种寄主植物的生产力。为了培育抗PVY的品种，识别植物与PVY的相互作用组并解读这些分子相互作用的生物学意义至关重要。我们以PVY编码的NIa-pro为诱饵，对cDNA文库进行了酵母双杂交（Y2H）筛选。IAAS被鉴定为NIa-pro蛋白的相互作用蛋白。通过靶向Y2H和双分子荧光互补（BiFC）试验证实了这种相互作用。NIa-pro与IAAS蛋白相互作用，从而提高了IAAS蛋白的稳定性。此外，还证明了NIa-pro和IAAS蛋白在细胞核和细胞质中的亚细胞定位。IAAS通过将游离IAA（活性形式）转化为结合IAA（非活性形式），在生长素信号传导中发挥关键的调节作用。在植物中瞬时沉默IAAS可减少PVY介导的症状诱导和病毒积累。相反，IAAS的过表达增强了受感染植物的症状诱导和病毒积累。此外，还发现生长素反应基因的表达在PVY感染期间下调。我们的研究结果表明，PVY NIa-pro蛋白可能通过调节生长素稳态来促进疾病发展。
