title: Core clock, SUB1, and ABAR genes mediate flooding and drought responses via alternative splicing in soybean.
abstract: Circadian clocks are a great evolutionary innovation and provide competitive advantage during the day/night cycle and under changing environmental conditions. The circadian clock mediates expression of a large proportion of genes in plants, achieving a harmonious relationship between energy metabolism, photosynthesis, and biotic and abiotic stress responses. Here it is shown that multiple paralogues of clock genes are present in soybean (Glycine max) and mediate flooding and drought responses. Differential expression of many clock and SUB1 genes was found under flooding and drought conditions. Furthermore, natural variation in the amplitude and phase shifts in PRR7 and TOC1 genes was also discovered under drought and flooding conditions, respectively. PRR3 exhibited flooding- and drought-specific splicing patterns and may work in concert with PRR7 and TOC1 to achieve energy homeostasis under flooding and drought conditions. Higher expression of TOC1 also coincides with elevated levels of abscisic acid (ABA) and variation in glucose levels in the morning and afternoon, indicating that this response to abiotic stress is mediated by ABA, endogenous sugar levels, and the circadian clock to fine-tune photosynthesis and energy utilization under stress conditions. It is proposed that the presence of multiple clock gene paralogues with variation in DNA sequence, phase, and period could be used to screen exotic germplasm to find sources for drought and flooding tolerance. Furthermore, fine tuning of multiple clock gene paralogues (via a genetic engineering approach) should also facilitate the development of flooding- and drought-tolerant soybean varieties.
authors: School of Human and Life Sciences, Canterbury Christ Church University, Canterbury CT1 1QU, UK naeem.syed@canterbury.ac.uk nsyed14@hotmail.com nguyenhenry@missouri.edu.
authors: Naeem H
authors: NH
authors: Syed
authors: National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
authors: Silvas J
authors: SJ
authors: Prince
authors: National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
authors: Raymond N
authors: RN
authors: Mutava
authors: National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
authors: Gunvant
authors: G
authors: Patil
authors: Song
authors: S
authors: Li
authors: National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
authors: Wei
authors: W
authors: Chen
authors: National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
authors: Valliyodan
authors: V
authors: Babu
authors: School of Human and Life Sciences, Canterbury Christ Church University, Canterbury CT1 1QU, UK.
authors: Trupti
authors: T
authors: Joshi
authors: Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
authors: Saad
authors: S
authors: Khan
authors: National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA naeem.syed@canterbury.ac.uk nsyed14@hotmail.com nguyenhenry@missouri.edu.
authors: Henry T
authors: HT
authors: Nguyen
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001683:Biological Clocks / Q000235:genetics*; D003517:Cyclopentanes / Q000378:metabolism; D055864:Droughts; D055868:Floods; D017343:Genes, Plant; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics; D016415:Sequence Alignment; D013025:Glycine max / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; D014157:Transcription Factors; C011006:jasmonic acid; D000040:Abscisic Acid
keywords: ABA; ABAR; SUB1.; alternative splicing; circadian clock; drought; flooding; jasmonic acid