conference schedule and program with abstracts - Horticulture ...
conference schedule and program with abstracts - Horticulture ...
conference schedule and program with abstracts - Horticulture ...
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P-57<br />
Phenotypic evaluation of ‘Thompson Seedless’ grapes transformed <strong>with</strong> AtNHX1 growing<br />
in hydroponics <strong>and</strong> potted soils<br />
M. Venier 1* , A. Bermejillo 1 , M.F. Filippini 1 , S.F. Alonso 1 , C. Agüero* 1 , A. D<strong>and</strong>ekar 2 , E.<br />
Blumwald 2<br />
1 Facultad de Ciencias Agrarias, Universidad Nac. de Cuyo, Luján de Cuyo, Mendoza, Argentina;<br />
2 Department of Plant Sciences, University of California, Davis, One Shield Ave, Davis,<br />
California, USA<br />
*Corresponding author: cbaguero@ucdavis.edu<br />
Overexpression of vacuolar Na + /H + antiport AtNHX1 has been reported to improve plant salt<br />
tolerance. We produced transgenic plants of Vitis vinifera cv. ‘Thompson Seedless’ via<br />
Agrobacterium tumefaciens carrying the gene encoding for AtNHX1 under the control of the<br />
constitutive promoter CaMV35S. Independent transgenic lines <strong>with</strong> improved tolerance of salt<br />
stress were selected in first round evaluations. The objective of this study was to analyze the<br />
response of the selected lines to NaCl stress in hydroponics <strong>and</strong> potted soils. Untransformed <strong>and</strong><br />
transgenic plants were acclimated to greenhouse conditions <strong>and</strong> grown hydroponically using<br />
Long Ashton nutrient solution. In the salinity treatments, NaCl concentrations were increased<br />
stepwise by 25 mM every 10 days up to 150 mM. In addition, untransformed <strong>and</strong> transgenic<br />
plants were grown in a mix of 7-3 grape pomace-s<strong>and</strong> soil <strong>and</strong> watered <strong>with</strong> Long Ashton<br />
nutrient solution <strong>with</strong> <strong>and</strong> <strong>with</strong>out increasing concentrations of NaCl. Analysis of plant growth<br />
variables confirmed the improved tolerance of the transgenic lines, which showed higher shoot<br />
length, leaf number, leaf area, <strong>and</strong> fresh <strong>and</strong> dry weight of shoots <strong>and</strong> roots. However, their<br />
better performance was not correlated <strong>with</strong> higher Na accumulation in root <strong>and</strong>/or shoot tissue<br />
compared to the untransformed controls. Na <strong>and</strong> Cl tissue contents were higher in plants grown<br />
in hydroponics; <strong>and</strong> roots accumulated 1.5-2.5 times more NaCl than aerial parts.<br />
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