A role for chloroplast-localized Thylakoid Formation 1 (THF1) in bacterial speck disease development.

Abstract

Coronatine (COR), a jasmonate mimic produced by Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) is required for full virulence of Pst DC3000 in tomato and Arabidopsis. COR is shown to induce a range of physiological processes including chlorosis, root growth inhibition and anthocyanin accumulation in tomato. To elucidate the host/signaling genes involved in COR-responses, we utilized a forward genetics approach using Nicotiana benthamiana and virus-induced gene silencing (VIGS) and identified genes that play a role in COR-mediated chlorosis. We designated these genes as altered COR response (ALC). When silenced, one gene designated ALC1 produced a hypersensitive/necrosis-like phenotype after COR application in a coronatine insensitive 1 (COI1)-dependent manner. In pathogenicity assays performed on Arabidopsis thylakoid formation 1 (thf1) knockout lines and SlALC1-silenced tomato plants, Pst DC3000 induced coalescing necrotic lesions in an accelerated manner. Furthermore, we showed that COR affects ALC1 localization in chloroplast in a COI1-dependent manner. In conclusion, our results show the potential of VIGS-based, forward genetic screens to identify new players in COR-mediated signal transduction.

• Authors: Tamding Wangdi, Srinivasa Rao Uppalapati, Satish Nagaraj, Choong-Min Ryu, Carol L Bender, Kirankumar S Mysore
• Journal: Plant signaling & behavior (Plant Signal Behav) Vol. 5 Issue 4 Pg. 425-7 (Apr 2010) ISSN: 1559-2324 [Electronic] United States
• PMID: 20339321 (Publication Type: Comment, Journal Article)