Improvement of Drought Tolerance and Grain Yield in Common Bean by Overexpressing Trehalose-6-Phosphate Synthase in Rhizobia

Book Title: NA
Year Published: 2008
Month Published: NA
Author: Suarez, Ramon ; Lara, Miguel ; Cevallos, Miguel A. ; Iturriaga, Gabriel ; Hernandez, Georgina ; Ramirez, Mario ; Wong,Arnoldo ; Orozco, Maria del Carmen ; Barraza, Aaron
Book Group Author: NA
Abstract:

Improving stress tolerance and yield in crops are major goals for agriculture. Here, we show a new strategy to increase drought tolerance and yield in legumes by overexpressing trehalose-6-phosphate synthase in the symbiotic bacterium Rhizobium etli. Phaseolus vulgaris (common beans) plants inoculated with R. etli overexpressing trehalose-6-phosphate synthase gene had more nodules with increased nitrogenase activity and higher biomass compared with plants inoculated with wild-type R. etli. In contrast, plants inoculated with an R. etli mutant in trehalose-6-phosphate synthase gene had fewer nodules and less nitrogenase activity and biomass. Three-week-old plants subjected to drought stress fully recovered whereas plants inoculated with a wild-type or mutant strain wilted and died. The yield of bean plants inoculated with R. etli overexpressing trehalose-6-phosphate synthase gene and grown with constant irrigation increased more than 50%. Macroarray analysis of 7,200 expressed sequence tags from nodules of plants inoculated with the strain overexpressing trehalose-6-phosphate synthase gene revealed upregulation of genes involved in stress tolerance and carbon and nitrogen metabolism, suggesting a signaling mechanism for trehalose. Thus, trehalose metabolism in rhizobia is key for signaling plant growth, yield, and adaptation to abiotic stress, and its manipulation has a major agronomical impact on leguminous plants.

Pages: 958 - 966
URL: http://0-search.ebscohost.com.catalog.library.colostate.edu/login.aspx?direct=true&AuthType=cookie,ip,url,cpid&custid=s4640792&db=agr&AN=IND44109836&site=ehost-live
Volume: 21
Number: 7
Journal: Molecular plant-microbe interactions : MPMI
Journal ISO: NA
Organization: NA
Publisher: NA
ISBN: NA
ISSN: 08940282
DOI: NA
Keywords:

root nodules, nitrogenase, enzymes, enzyme activity, drymatter accumulation, expressed sequence tags, signal transduction,irrigation, microarray technology, protein synthesis, drought tolerance,water stress, Phaseolus vulgaris, beans, drought, symbionts, symbiosis,crop yield, Rhizobium etli

Source: EBSCO
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