01941naa a2200265 a 450000100080000000500110000800800410001910000230006024501700008326000090025352011220026265000110138465000220139565000220141765000120143965000220145170000170147370000270149070000210151770000160153870000250155470000220157970000210160177300530162221606392024-01-10       2004    bl uuuu     u00u1 u    #d1 aMOLINARI, H. B. C.  aOsmotic adjustment in transgenic citrus rootstock Carrizo citrange (Citrus sinensis Osb. x Poncirus trifoliata L. Raf.) overproducing proline.h[electronic resource]  c2004  aIn the present study, we have analyzed transformed plants of the citrus rootstock Carrizo citrange constitutively expressing a Δ1-pyrroline-5-carboxylate synthetase mutant gene (p5cs), which encodes the rate-limiting enzyme of the proline biosynthetic pathway. Transgenic plants grew normally in vivo and accumulated high levels of proline in the leaves. In well-watered conditions, the photosynthetic rate of Carrizo citrange transgenic plants was not significantly different from the non-transformed control. The transgenic plants presented superior osmotic adjustment and significantly higher photosynthetic rate than the control plants after 15 days without watering. Under water deficit, the leaf water potential of non-transformed plants was close to zero after 17 days, and the photosynthetic rate was almost null 2 days later. On the other hand, in transgenic plants similar measurements were only observed after 24 days of water stress. The use of citrus rootstocks with increased proline accumulation appears to be a promising approach to maintain the productivity of plants under drought stress condition.  aCitrus  aDrought tolerance  aOsmotic treatment  aProline  aTransgenic plants1 aMARUR, C. J.1 aBESPALHOK FILHO, J. C.1 aKOBAYASHI, A. K.1 aPILEGGI, M.1 aLEITE JÚNIOR, R. P.1 aPEREIRA, L. F. P.1 aVIEIRA, L. G. E.  tPlant Sciencegv. 167, n. 6, p. 1375-1381, 2004.