title: Physiological and molecular analysis of the interaction between aluminium toxicity and drought stress in common bean (Phaseolus vulgaris).
abstract: Aluminium (Al) toxicity and drought are two major factors limiting common bean (Phaseolus vulgaris) production in the tropics. Short-term effects of Al toxicity and drought stress on root growth in acid, Al-toxic soil were studied, with special emphasis on Al-drought interaction in the root apex. Root elongation was inhibited by both Al and drought. Combined stresses resulted in a more severe inhibition of root elongation than either stress alone. This result was different from the alleviation of Al toxicity by osmotic stress (-0.60 MPa polyethylene glycol) in hydroponics. However, drought reduced the impact of Al on the root tip, as indicated by the reduction of Al-induced callose formation and MATE expression. Combined Al and drought stress enhanced up-regulation of ACCO expression and synthesis of zeatin riboside, reduced drought-enhanced abscisic acid (ABA) concentration, and expression of NCED involved in ABA biosynthesis and the transcription factors bZIP and MYB, thus affecting the regulation of ABA-dependent genes (SUS, PvLEA18, KS-DHN, and LTP) in root tips. The results provide circumstantial evidence that in soil, drought alleviates Al injury, but Al renders the root apex more drought-sensitive, particularly by impacting the gene regulatory network involved in ABA signal transduction and cross-talk with other phytohormones necessary for maintaining root growth under drought.
authors.affiliation: Institute of Plant Nutrition, Leibniz Universität Hannover, Herrenhaeuser Str. 2, D-30419 Hannover, Germany.
authors.forename: Zhong-Bao
authors.initials: ZB
authors.lastname: Yang
authors.forename: Dejene
authors.initials: D
authors.lastname: Eticha
authors.forename: Alfonso
authors.initials: A
authors.lastname: Albacete
authors.forename: Idupulapati Madhusudana
authors.initials: IM
authors.lastname: Rao
authors.forename: Thomas
authors.initials: T
authors.lastname: Roitsch
authors.forename: Walter Johannes
authors.initials: WJ
authors.lastname: Horst
mesh_terms: D000040:Abscisic Acid / Q000096:biosynthesis; D000535:Aluminum / Q000633:toxicity*; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics; D002473:Cell Wall / Q000187:drug effects / Q000235:genetics; D003105:Colombia; D003583:Cytokinins / Q000096:biosynthesis*; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D005838:Genotype; D005936:Glucans / Q000378:metabolism; D007541:Isopentenyladenosine / Q000031:analogs & derivatives / Q000378:metabolism; D008954:Models, Biological; D009997:Osmotic Pressure / Q000187:drug effects; D027805:Phaseolus / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics*
chemical_list: D003583:Cytokinins; D005936:Glucans; D000040:Abscisic Acid; D007541:Isopentenyladenosine; C009699:zeatin riboside; C048306:callose; D000535:Aluminum