title: Arabidopsis Transcription Factors SPL1 and SPL12 Confer Plant Thermotolerance at Reproductive Stage.
abstract: Plant reproductive organs are vulnerable to heat, but regulation of heat-shock responses in inflorescence is largely uncharacterized. Here, we report that two of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcriptional factors in Arabidopsis, SPL1 and SPL12, act redundantly in thermotolerance at the reproductive stage. The spl1-1 spl12-1 inflorescences displayed hypersensitivity to heat stress, whereas overexpression of SPL1 or SPL12 enhanced the thermotolerance in both Arabidopsis and tobacco. RNA sequencing revealed 1939 upregulated and 1479 downregulated genes in wild-type inflorescence upon heat stress, among which one-quarter (1,040) was misregulated in spl1-1 spl12-1, indicating that SPL1 and SPL12 contribute greatly to the heat-triggered transcriptional reprogramming in inflorescence. Notably, heat stress induced a large number of abscisic acid (ABA) responsive genes, of which ∼39% were disturbed in heat induction in spl1-1 spl12-1 inflorescence. Preapplication of ABA and overexpression of SPL1 restored the inflorescence thermotolerance in spl1-1 spl12-1 and in the ABA biosynthesis mutant aba2-1, but not in the pyl sextuple mutant defective in ABA receptors PYR1/PYL1/PYL2/PYL4/PYL5/PYL8. Thus, inflorescence thermotolerance conferred by SPL1 and SPL2 involves PYL-mediated ABA signaling. The molecular network consisting of SPL1 and SPL12 illustrated here shed new light on the mechanisms of plant thermotolerance at the reproductive stage.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, University of CAS, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Lu-Men
authors.initials: LM
authors.lastname: Chao
authors.affiliation: School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China.
authors.forename: Yao-Qian
authors.initials: YQ
authors.lastname: Liu
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, University of CAS, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Dian-Yang
authors.initials: DY
authors.lastname: Chen
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, University of CAS, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Xue-Yi
authors.initials: XY
authors.lastname: Xue
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, University of CAS, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Ying-Bo
authors.initials: YB
authors.lastname: Mao
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, University of CAS, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China; Plant Science Research Center, Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai 201602, People's Republic of China. Electronic address: xychen@sibs.ac.cn.
authors.forename: Xiao-Ya
authors.initials: XY
authors.lastname: Chen
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D055785:Gene Knockdown Techniques; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D012098:Reproduction; D012639:Seeds; D015398:Signal Transduction; D000071436:Thermotolerance; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D011506:Proteins; C509995:Spl12 protein, Arabidopsis; D014157:Transcription Factors; D000040:Abscisic Acid; C088014:spore photoproduct lyase
keywords: SPL; abscisic acid; inflorescence; plant thermotolerance; transcription factor