The phytoplasmal virulence factor TENGU causes plant sterility by downregulating of the jasmonic acid and auxin pathways

• DOI: 10.1038/srep07399
• Publication Date: 2014-12-10T10:05:31Z
• Authors: Nami Minato; Misako Himeno; Ayaka Hoshi; Kensaku Maejima; Ken Komatsu; Yumiko Takebayashi; Hiroyuki Kasahara; Akira Yusa; Yasuyuki Yamaji; Kenro Oshima; Yuji Kamiya; Shigetou Namba
• Keywords: 0301 basic medicine; Phytoplasma; Plant Infertility; Indoleacetic Acids; Arabidopsis Proteins; Arabidopsis; Down-Regulation; Cyclopentanes; Flowers; Article; DNA-Binding Proteins; 03 medical and health sciences; Bacterial Proteins; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Oxylipins; Peptides; Signal Transduction; Transcription Factors

Despite plants infected by pathogens are often unable to produce offspring, it remains unclear how sterility is induced in host plants. In this study, we demonstrate that TENGU, a phytoplasmal virulence peptide known as a dwarfism inducer, acts as an inducer of sterility. Transgenic expression of TENGU induced both male and female sterility in Arabidopsis thaliana flowers similar to those observed in double knockout mutants of auxin response factor 6 (ARF6) and ARF8, which are known to regulate floral development in a jasmonic acid (JA)-dependent manner. Transcripts of ARF6 and ARF8 were significantly decreased in both tengu-transgenic and phytoplasma-infected plants. Furthermore, JA and auxin levels were actually decreased in tengu-transgenic buds, suggesting that TENGU reduces the endogenous levels of phytohormones by repressing ARF6 and ARF8, resulting in impaired flower maturation. TENGU is the first virulence factor with the effects on plant reproduction by perturbation of phytohormone signaling.