title: The sunflower transcription factor HaHB11 confers tolerance to water deficit and salinity to transgenic Arabidopsis and alfalfa plants.
abstract: Homeodomain-leucine zipper (HD-Zip) transcription factors are unique to the plant kingdom; members of subfamily I are known to be involved in abiotic stress responses. HaHB11 belongs to this subfamily and it was previously shown that it is able to confer improved yield and tolerance to flooding via a quiescent strategy. Here we show that HaHB11 expression is induced by ABA, NaCl and water deficit in sunflower seedlings and leaves. Arabidopsis transgenic plants expressing HaHB11, controlled either by its own promoter or by the constitutive 35S CaMV, presented rolled leaves and longer roots than WT when grown under standard conditions. In addition, these plants showed wider stems and more vascular bundles. To deal with drought, HaHB11 transgenic plants closed their stomata faster and lost less water than controls, triggering an enhanced tolerance to such stress condition and also to salinity stress. Concomitantly, ABA-synthesis and sensing related genes were differentially regulated in HaHB11 transgenic plants. Either under long-term salinity stress or mild drought stress, HaHB11 transgenic plants did not exhibit yield penalties. Moreover, alfalfa transgenic plants were generated which also showed enhanced drought tolerance. Altogether, the results indicated that HaHB11 was able to confer drought and salinity tolerance via a complex mechanism which involves morphological, physiological and molecular changes.
authors.affiliation: Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, CONICET, Facultad de Bioquímica y Ciencias Biológicas, Colectora Ruta Nacional 168 km 0, 3000, Santa Fe, Argentina.
authors.forename: Julieta V
authors.initials: JV
authors.lastname: Cabello
authors.affiliation: Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, CONICET, Facultad de Bioquímica y Ciencias Biológicas, Colectora Ruta Nacional 168 km 0, 3000, Santa Fe, Argentina.
authors.forename: Jorge I
authors.initials: JI
authors.lastname: Giacomelli
authors.affiliation: Instituto de Genética "Ewald A. Favret", CICVyA, INTA De los Reseros y Cabañas S/N; CC 25 (1712), Castelar, Buenos Aires, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Gómez
authors.affiliation: Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral, CONICET, Facultad de Bioquímica y Ciencias Biológicas, Colectora Ruta Nacional 168 km 0, 3000, Santa Fe, Argentina. Electronic address: rchan@fbcb.unl.edu.ar.
authors.forename: Raquel L
authors.initials: RL
authors.lastname: Chan
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics / Q000502:physiology; D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018533:Biomass; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D006368:Helianthus / Q000235:genetics*; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016350:Leucine Zippers / Q000235:genetics; D000455:Medicago sativa / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011401:Promoter Regions, Genetic; D055049:Salt Tolerance / Q000502:physiology*; D036226:Seedlings; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014867:Water
chemical_list: D029681:Arabidopsis Proteins; C108566:HAHR1 protein, plant; D018398:Homeodomain Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D014867:Water
keywords: Drought tolerance; HaHB11; Homeodomain-leucine zipper I; Seed yield; Transcription factor; Vascular bundles