15
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      The role of cytokinins in responses to water deficit in tobacco plants over-expressing trans-zeatin O-glucosyltransferase gene under 35S or SAG12 promoters.

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The impact of water deficit progression on cytokinin (CK), auxin and abscisic acid (ABA) levels was followed in upper, middle and lower leaves and roots of Nicotiana tabacum L. cv. Wisconsin 38 plants [wild type (WT)]. ABA content was strongly increased during drought stress, especially in upper leaves. In plants with a uniformly elevated total CK content, expressing constitutively the trans-zeatin O-glucosyltransferase gene (35S::ZOG1), a delay in the increase of ABA was observed; later on, ABA levels were comparable with those of WT. As drought progressed, the bioactive CK content in leaves gradually decreased, being maintained longer in the upper leaves of all tested genotypes. Under severe stress (11 d dehydration), a large stimulation of cytokinin oxidase/dehydrogenase (CKX) activity was monitored in lower leaves, which correlated well with the decrease in bioactive CK levels. This suggests that a gradient of bioactive CKs in favour of upper leaves is established during drought stress, which might be beneficial for the preferential protection of these leaves. During drought, significant accumulation of CKs occurred in roots, partially because of decreased CKX activity. Simultaneously, auxin increased in roots and lower leaves. This indicates that both CKs and auxin play a role in root response to severe drought, which involves the stimulation of primary root growth and branching inhibition.

          Related collections

          Author and article information

          Journal
          Plant Cell Environ
          Plant, cell & environment
          Wiley
          1365-3040
          0140-7791
          Mar 2008
          : 31
          : 3
          Affiliations
          [1 ] Institute of Experimental Botany AS CR, Rozvojova 263, 165 02 Prague 6, Czech Republic.
          Article
          PCE1766
          10.1111/j.1365-3040.2007.01766.x
          18088334
          0f2c9960-e367-4c7f-8a13-66dc52964b10
          History

          Comments

          Comment on this article