title: The RING Finger E3 Ligase SpRing is a Positive Regulator of Salt Stress Signaling in Salt-Tolerant Wild Tomato Species.
abstract: Protein ubiquitination in plants plays critical roles in many biological processes, including adaptation to abiotic stresses. Previously, RING finger E3 ligase has been characterized during salt stress response in several plant species, but little is known about its function in tomato. Here, we report that SpRing, a stress-inducible gene, is involved in salt stress signaling in wild tomato species Solanum pimpinellifolium 'PI365967'. In vitro ubiquitination assay revealed that SpRing is an E3 ubiquitin ligase and the RING finger conserved region is required for its activity. SpRing is expressed in all tissues of wild tomato and up-regulated by salt, drought and osmotic stresses, but repressed by low temperature. Green fluorescent protein (GFP) fusion analysis showed that SpRing is localized at the endoplasmic reticulum. Silencing of SpRing through a virus-induced gene silencing approach led to increased sensitivity to salt stress in wild tomato. Overexpression of SpRing in Arabidopsis thaliana resulted in enhanced salt tolerance during seed germination and early seedling development. The expression levels of certain key stress-related genes are altered both in SpRing-overexpressing Arabidopsis plants and virus-induced gene silenced tomato seedlings. Taken together, our results indicate that SpRing is involved in salt stress and functions as a positive regulator of salt tolerance.
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany Chinese Academy of Sciences, Beijing 100093, China University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Shilian
authors.initials: S
authors.lastname: Qi
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany Chinese Academy of Sciences, Beijing 100093, China University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Qingfang
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Huishan
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Wenhao
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany Chinese Academy of Sciences, Beijing 100093, China xjhua@ibcas.ac.cn.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Hua
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified; D021381:Protein Transport / Q000187:drug effects; D054829:RING Finger Domains; D055049:Salt Tolerance / Q000187:drug effects* / Q000235:genetics; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D032322:Solanum / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D013347:Subcellular Fractions / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride; D012964:Sodium; D006861:Hydrogen Peroxide; D044767:Ubiquitin-Protein Ligases
keywords: E3 Ligase; RING-H2; salt tolerance; Solanum pimpinellifolium; VIGS