title: Light affects salt stress-induced transcriptional memory of P5CS1 in Arabidopsis.
abstract: To cope with environmental stresses, plants often adopt a memory response upon primary stress exposure to facilitate a quicker and stronger reaction to recurring stresses. However, it remains unknown whether light is involved in the manifestation of stress memory. Proline accumulation is a striking metabolic adaptation of higher plants during various environmental stresses. Here we show that salinity-induced proline accumulation is memorable and HY5-dependent light signaling is required for such a memory response. Primary salt stress induced the expression of Δ1-pyrroline-5-carboxylate synthetase 1 (P5CS1), encoding a proline biosynthetic enzyme and proline accumulation, which were reduced to basal level during the recovery stage. Reoccurring salt stress-induced stronger P5CS1 expression and proline accumulation were dependent upon light exposure during the recovery stage. Further studies demonstrated that salt-induced transcriptional memory of P5CS1 is associated with the retention of increased H3K4me3 level at P5CS1 during the recovery stage. HY5 binds directly to light-responsive element, C/A-box, in the P5CS1 promoter. Deletion of the C/A-box or hy5 hyh mutations caused rapid reduction of H3K4me3 level at P5CS1 during the recovery stage, resulting in impairment of the stress memory response. These results unveil a previously unrecognized mechanism whereby light regulates salt-induced transcriptional memory via the function of HY5 in maintaining H3K4me3 level at the memory gene.
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.|College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xuan Jun
authors.initials: XJ
authors.lastname: Feng
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.|College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jing Rui
authors.initials: JR
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Shi Lian
authors.initials: SL
authors.lastname: Qi
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Qing Fang
authors.initials: QF
authors.lastname: Lin
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China jinjb@ibcas.ac.cn xjhua@ibcas.ac.cn.
authors.forename: Jing Bo
authors.identifier: 0000-0001-5847-5138
authors.initials: JB
authors.lastname: Jin
authors.affiliation: Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; jinjb@ibcas.ac.cn xjhua@ibcas.ac.cn.
authors.forename: Xue Jun
authors.initials: XJ
authors.lastname: Hua
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D050698:Glutamate-5-Semialdehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D008027:Light; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000528:radiation effects; D011758:Pyrroles; D012492:Salts / Q000737:chemistry*; D012639:Seeds / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; C109254:HY5 protein, Arabidopsis; D006657:Histones; D009097:Multienzyme Complexes; D009687:Nuclear Proteins; D011758:Pyrroles; D012492:Salts; C583835:delta(1)-pyrroline-5-carboxylate synthetase, Arabidopsis; C015485:delta-1-pyrroline-5-carboxylate; D050698:Glutamate-5-Semialdehyde Dehydrogenase; D017853:Phosphotransferases (Alcohol Group Acceptor)
keywords: H3K4me3; HY5/HYH; P5CS1; light; transcriptional memory