title: The Alfin-like homeodomain finger protein AL5 suppresses multiple negative factors to confer abiotic stress tolerance in Arabidopsis.
abstract: Plant homeodomain (PHD) finger proteins affect processes of growth and development by changing transcription and reading epigenetic histone modifications, but their functions in abiotic stress responses remain largely unclear. Here we characterized seven Arabidopsis thaliana Alfin1-like PHD finger proteins (ALs) in terms of the responses to abiotic stresses. ALs localized to the nucleus and repressed transcription. Except AL6, all the ALs bound to G-rich elements. Mutations of the amino acids at positions 34 and 35 in AL6 caused loss of ability to bind to G-rich elements. Expression of the AL genes responded differentially to osmotic stress, salt, cold and abscisic acid treatments. AL5-over-expressing plants showed higher tolerance to salt, drought and freezing stress than Col-0. Consistently, al5 mutants showed reduced stress tolerance. We used ChIP-Seq assays to identify eight direct targets of AL5, and found that AL5 binds to the promoter regions of these genes. Knockout mutants of five of these target genes exhibited varying tolerances to stresses. These results indicate that AL5 inhibits multiple signaling pathways to confer stress tolerance. Our study sheds light on mechanisms of AL5-mediated signaling in abiotic stress responses, and provides tools for improvement of stress tolerance in crop plants.
authors.affiliation: State Key Lab of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beichen West Road, Chaoyang District, Beijing, 100101, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Yu-Qin
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Tao
authors.forename: Hao-Wei
authors.initials: HW
authors.lastname: Chen
authors.forename: Qing-Tian
authors.initials: QT
authors.lastname: Li
authors.forename: Wan-Ke
authors.initials: WK
authors.lastname: Zhang
authors.forename: Biao
authors.initials: B
authors.lastname: Ma
authors.forename: Qing
authors.initials: Q
authors.lastname: Lin
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Zhang
authors.forename: Shou-Yi
authors.initials: SY
authors.lastname: Chen
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D005615:Freezing; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000378:metabolism; D030821:Plants, Genetically Modified; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C000603839:AL5 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D010937:Plant Growth Regulators; D012097:Repressor Proteins; D014157:Transcription Factors; D012965:Sodium Chloride; D000040:Abscisic Acid
keywords: Alfin1; Arabidopsis; ChIP-Seq; abiotic stress; plant homeodomain; transcriptional repressor