Articles

Drought stress response in maize: molecular, morphological and physiological analysis of tolerant and sensitive genotypes


Abstract


The aim of this work was to develop a physiological method based on transpiration in combination with molecular
methods, i.e., dehydrin gene expression analysis, for identifying the reactions of maize (Zea mays L.) plants that
display different levels of tolerance to drought stress during the generative growth stage. Drought stress was
induced in two genotypes, 2087 and 2637, by four irrigation treatments. The rate of transpiration and the expression
of the dehydrin genes ZmDHN1 and ZmDHN2 were dependent on genotype and duration and intensity
of stress. The yield components were affected by the level of dehydrin gene expression and transpiration rate.
Compared with genotype 2637, genotype 2087 a) maintained higher transpiration intensity, even under strong
drought stress conditions, b) exhibited an earlier onset and a higher level of expression both at a lower stress
intensity and during the initial phases of the stress reaction, c) showed higher values of yield components, and
d) was characterized by a lower water-use efficiency of cob yield. Drought tolerance is of increasing importance
and is one of the breeding targets in maize. However, traditional breeding methods have numerous limitations.
The simultaneous use of new molecular genetic techniques and physiological methods could therefore help to
elucidate the genetic and physiological basis of plant responses to drought stress and provide more accurate
evaluation for screening parental breeding material.


Keywords

Maize, Sap flow, Drought stress, Water-Use Efficiency, Dehydrin

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013