title: Establishment of a transgenic hairy root system in wild and domesticated watermelon (Citrullus lanatus) for studying root vigor under drought.
abstract: Root vigor is an important trait for the growth of terrestrial plants, especially in water-deficit environments. Although deserts plants are known for their highly developed root architecture, the molecular mechanism responsible for this trait has not been determined. Here we established an efficient protocol for the genetic manipulation of two varieties of watermelon plants: a desert-grown wild watermelon that shows vigorous root growth under drought, and a domesticated cultivar showing retardation of root growth under drought stress. Agrobacterium rhizogenes-mediated transgenic hairy roots were efficiently induced and selected from the hypocotyls of these plants. Transgenic GUS expression was detected in the roots by RT-PCR and histochemical GUS staining. Moreover, a liquid culture system for evaluating their root growth was also established. Interestingly, growth of the hairy roots derived from domesticated variety of watermelon strongly inhibited under high osmotic condition, whereas the hairy roots derived from wild variety of watermelon retained substantial growth rates under the stress condition. The new protocol presented here offers a powerful tool for the comparative study of the molecular mechanism underlying drought-induced root growth in desert plants.
authors.affiliation: Nara Institute of Science and Technology, Graduate School of Biological Sciences, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Kajikawa
authors.forename: Kaoru
authors.initials: K
authors.lastname: Morikawa
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Abe
authors.forename: Akiho
authors.initials: A
authors.lastname: Yokota
authors.forename: Kinya
authors.initials: K
authors.lastname: Akashi
mesh_terms: D029773:Citrullus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D003681:Dehydration / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D003889:Desert Climate; D055864:Droughts; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water
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