title: Cellular and molecular insight into the inhibition of primary root growth of Arabidopsis induced by peptaibols, a class of linear peptide antibiotics mainly produced by Trichoderma spp.
abstract: Trichoderma spp. are well known biocontrol agents that produce a variety of antibiotics. Peptaibols are a class of linear peptide antibiotics mainly produced by Trichoderma Alamethicin, the most studied peptaibol, is reported as toxic to plants at certain concentrations, while the mechanisms involved are unclear. We illustrated the toxic mechanisms of peptaibols by studying the growth-inhibitory effect of Trichokonin VI (TK VI), a peptaibol from Trichoderma longibrachiatum SMF2, on Arabidopsis primary roots. TK VI inhibited root growth by suppressing cell division and cell elongation, and disrupting root stem cell niche maintenance. TK VI increased auxin content and disrupted auxin response gradients in root tips. Further, we screened the Arabidopsis TK VI-resistant mutant tkr1. tkr1 harbors a point mutation in GORK, which encodes gated outwardly rectifying K(+)channel proteins. This mutation alleviated TK VI-induced suppression of K(+)efflux in roots, thereby stabilizing the auxin gradient. The tkr1 mutant also resisted the phytotoxicity of alamethicin. Our results indicate that GORK channels play a key role in peptaibol-plant interaction and that there is an inter-relationship between GORK channels and maintenance of auxin homeostasis. The cellular and molecular insight into the peptaibol-induced inhibition of plant root growth advances our understanding of Trichoderma-plant interactions.
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors: Wei-Ling
authors: WL
authors: Shi
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China.
authors: Xiu-Lan
authors: XL
authors: Chen
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China.
authors: Li-Xia
authors: LX
authors: Wang
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China.
authors: Zhi-Ting
authors: ZT
authors: Gong
authors: State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors: Shuyu
authors: S
authors: Li
authors: Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan 250100, China.
authors: Chun-Long
authors: CL
authors: Li
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China.
authors: Bin-Bin
authors: BB
authors: Xie
authors: Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan 250100, China.
authors: Wei
authors: W
authors: Zhang
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China.
authors: Mei
authors: M
authors: Shi
authors: State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors: Chuanyou
authors: C
authors: Li
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China.
authors: Yu-Zhong
authors: YZ
authors: Zhang
authors: State Key Laboratory of Microbial Technology, Marine Biotechnology Research, Shandong University, Jinan 250100, China xysong@sdu.edu.cn.
authors: Xiao-Yan
authors: XY
authors: Song
mesh_terms: D000408:Alamethicin / Q000031:analogs & derivatives / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D003001:Cloning, Molecular; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000187:drug effects / Q000254:growth & development; D009154:Mutation / Q000235:genetics; D054848:Peptaibols / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development*; D015221:Potassium Channels / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D055153:Stem Cell Niche / Q000187:drug effects; D014242:Trichoderma / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D054848:Peptaibols; D010455:Peptides; D015221:Potassium Channels; D000408:Alamethicin; C092827:trichokonin VI
keywords: Arabidopsis thaliana; GORK; Trichoderma; Trichokonin VI.; auxin; peptaibols