title: A nuclear calcium-sensing pathway is critical for gene regulation and salt stress tolerance in Arabidopsis.
abstract: Salt stress is an important environmental factor that significantly limits crop productivity worldwide. Studies on responses of plants to salt stress in recent years have identified novel signaling pathways and have been at the forefront of plant stress biology and plant biology in general. Thus far, research on salt stress in plants has been focused on cytoplasmic signaling pathways. In this study, we discovered a nuclear calcium-sensing and signaling pathway that is critical for salt stress tolerance in the reference plant Arabidopsis. Through a forward genetic screen, we found a nuclear-localized calcium-binding protein, RSA1 (SHORT ROOT IN SALT MEDIUM 1), which is required for salt tolerance, and identified its interacting partner, RITF1, a bHLH transcription factor. We show that RSA1 and RITF1 regulate the transcription of several genes involved in the detoxification of reactive oxygen species generated by salt stress and that they also regulate the SOS1 gene that encodes a plasma membrane Na(+)/H(+) antiporter essential for salt tolerance. Together, our results suggest the existence of a novel nuclear calcium-sensing and -signaling pathway that is important for gene regulation and salt stress tolerance.
authors.affiliation: Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland, United States of America.
authors.forename: Qingmei
authors.initials: Q
authors.lastname: Guan
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wu
authors.forename: Xiule
authors.initials: X
authors.lastname: Yue
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhu
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D002135:Calcium-Binding Proteins; D017382:Reactive Oxygen Species; D012965:Sodium Chloride; C587169:At2g03150 protein, Arabidopsis; C587168:RITF1 protein, Arabidopsis