| Abstract Detail
Evolution of Hyphal Function and Development Luo, Yongping [1], Xu, JinRong [2]. The FgKin1 kinase localizes to the septal pore and differentially regulates the localization of two beta-tubulins in Fusarium graminearum. Protein kinases belonging to the Kin1/Par-1/MARK family are known to regulate cell polarity, microtubule stability, and other cellular processes in yeasts and animals. Kin1 orthologs are conserved but none of them have been functionally characterized in filamentous ascomycetes. In the wheat scab fungus Fusarium graminearum, deletion of FgKIN1 resulted in a reduction in growth rate, conidiation, and virulence. The Fgkin1 mutant was defective in conidium morphology, forcible discharge of ascospores, and auto-inhibition of ascospore germination inside perithecia. It also had increased sensitivity to hyperosmotic and cell wall stresses. Glycogen accumulation was reduced in conidia but increased in young asci of the Fgkin1 mutant. In spores and hyphae, FgKin1-GFP localized to the center of septal pores on the tip side of septa. Its association with microtubule bundling at the septal pore may be related to septum functions. Like other Fusarium pathogens, F. graminearum contains two β-tubulin genes. Interestingly, deletion of FgKin1 had no obvious effect on Tub2 but disrupted the localization of Tub1 to the microtubules. In the Fgkin1 mutant, Tub1 became aggregated at the microtubule-organizing center (MTOC)-like spots adjacent to the nucleus. In the rice blast fungus, MoKIN1 had similar function and subcellular localization with FgKIN1. When the FgKIN1S172A kinase dead allele was transformed into the Fgkin1 mutant, defects in growth, conidiation, and virulence were not affected but ascospore discharge was partially rescued. However, FgKin1 still localized to the septal pore. Overall, our data indicate that FgKin1 has both kinase-dependent and independent functions and it differentially regulates the two β-tubulins in F. graminearum. Although it is dispensable for polarized growth, FgKin1 plays a critical role in the regulation of ascospore release, germination, and plant infection.
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1 - Northwest A&F University, College of Plant Protection, Yangling, Shaanxi, 712100, China
2 - Purdue University, Dept. of Botany and Plant Pathology, West Lafayette, IN, 47907, USA
Keywords:
none specified
Presentation Type: Symposium or Colloquium Presentation
Session: SY6
Location: Room 104 AB/Kellogg Hotel and Conference Center
Date: Tuesday, June 10th, 2014
Time: 2:00 PM
Number: SY6003
Abstract ID:23
Candidate for Awards:None |
