title: Erianthus arundinaceus HSP70 (EaHSP70) Acts as a Key Regulator in the Formation of Anisotropic Interdigitation in Sugarcane (Saccharum spp. hybrid) in Response to Drought Stress.
abstract: Plant growth during abiotic stress is a long sought-after trait especially in crop plants in the context of global warming and climate change. Previous studies on leaf epidermal cells have revealed that during normal growth and development, adjacent cells interdigitate anisotropically to form cell morphological patterns known as interlocking marginal lobes (IMLs), involving the cell wall-cell membrane-cortical actin continuum. IMLs are growth-associated cell morphological changes in which auxin-binding protein (ABP), Rho GTPases and actin are known to play important roles. In the present study, we investigated the formation of IMLs under drought stress and found that Erianthus arundinaceus, a drought-tolerant wild relative of sugarcane, develops such growth-related cell morphological patterns under drought stress. Using confocal microscopy, we showed an increasing trend in cortical F-actin intensity in drought-tolerant plants with increasing soil moisture stress. In order to check the role of drought tolerance-related genes in IML formation under soil moisture stress, we adopted a structural data mining strategy and identified indirect connections between the ABPs and heat shock proteins (HSPs). Initial experimental evidence for this connection comes from the high transcript levels of HSP70 observed in drought-stressed Erianthus, which developed anisotropic interdigitation, i.e. IMLs. Subsequently, by overexpressing the E. arundinaceus HSP70 gene (EaHSP70) in sugarcane (Saccharum spp. hybrid), we confirm the role of HSP70 in the formation of anisotropic interdigitation under drought stress. Taken together, our results suggest that EaHSP70 acts as a key regulator in the formation of anisotropic interdigitation in drought-tolerant plants (Erianthus and HSP70 transgenic sugarcane) under moisture stress in an actin-mediated pathway. The possible biological significance of the formation of drought-associated interlocking marginal lobes (DaIMLs) in sugarcane plants upon drought stress is discussed.
authors.affiliation: Sugarcane Breeding Institute, ICAR, Coimbatore 641007, India monian_52@yahoo.com dpsdevi@gmail.com.
authors.forename: Sruthy Maria
authors.initials: SM
authors.lastname: Augustine
authors.affiliation: Present address: Max Planck Institute for Heart and Lungs Research, Bad Nauheim, Germany. monian_52@yahoo.com dpsdevi@gmail.com.
authors.forename: Anoop V
authors.initials: AV
authors.lastname: Cherian
authors.affiliation: Sugarcane Breeding Institute, ICAR, Coimbatore 641007, India Present address: Indian Institute of Rice Research, ICAR, Hyderabad, India. monian_52@yahoo.com dpsdevi@gmail.com.
authors.forename: Divya P
authors.initials: DP
authors.lastname: Syamaladevi
authors.affiliation: Sugarcane Breeding Institute, ICAR, Coimbatore 641007, India monian_52@yahoo.com dpsdevi@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Subramonian
mesh_terms: D000199:Actins / Q000378:metabolism; D016880:Anisotropy; D002462:Cell Membrane / Q000378:metabolism; D019295:Computational Biology; D057225:Data Mining; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D008954:Models, Biological; D009997:Osmotic Pressure; D019441:Plant Epidermis / Q000166:cytology; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000235:genetics; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D025941:Protein Interaction Mapping; D015203:Reproducibility of Results; D031786:Saccharum / Q000235:genetics* / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D000199:Actins; D018840:HSP70 Heat-Shock Proteins; D010940:Plant Proteins
keywords: Actin; Drought stress tolerance; EaHSP70; Erianthus arundinaceus; Interlocking marginal lobes; Sugarcane