30 research outputs found
Drought stress response in wheat: physiological and molecular analysis of resistant and sensitive genotypes
Water deficit is a severe environmental stress and the major
constraint on plant productivity with an evident effect on
plant growth. The aim of this work was to study Triticum and Aegilops seedlings differing in their response to drought stress at the physiological and molecular levels.
The identification of resistant and sensitive genotypes was
firstly based on the relative water content (RWC) measurement.
Further characterization of genotypes contrasting in
their response to water stress was performed at the physiological
level by determination of RWC, water loss rate
(WLR) and free proline content after different hours of
dehydration. Modification in the expression level of five
dehydrin (DHN) genes was also analysed by reverse
transcription–polymerase chain reaction (RT-PCR). Five
cDNAs coding for different DHNs were identified and
characterized. These genes are not expressed in the wellwatered
plants, but only in the stressed plants. Four of these
cDNAs are related to novel DHN sequences. The results
obtained clearly indicate a relation between the expression
of these genes and tissue water content. In particular, in the
resistant genotypes the expression of DHN genes is initiated
even though tissue hydration levels are still high, indicating
also in wheat the involvement of these proteins in
water retention