ARS | Publication request: EVIDENCE FOR THE MITIGATION OF GIBBERELLIN DEFICIENCY SYMPTOMS BY ROOT ZONE CALCIUM IN GA-DEFICIENT MUTANTS OF POTATO

Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2004
Publication Date: August 10, 2004
Citation: Vega, S.E., Palta, J.P., Bamberg, J.B. 2005. Evidence for the mitigation of gibberellin deficiency symptoms by root zone calcium in ga-deficient mutants of potato. American Journal of Potato Research. 82:94.

Technical Abstract: GA-deficient mutants from Solanum species (especially S. andigena) have been isolated and studied. These mutants lack the ability to produce adequate amounts of gibberellin for normal growth, resulting in a rosette type growth and very short internodes. The effect of root zone calcium was investigated on GA-deficient mutants grown both in vitro and under greenhouse conditions. In vitro experiments consisted of growing various diploid and tetraploid GA mutants on sterilized MS media containing different levels of calcium and GA3. Results showed that plants under higher calcium concentrations were able to grow with much more normal appearance (i.e. plant height and internode length) than those growing under low calcium levels. Thus high root zone calcium (>2000 ppm) was able to mitigate the effects of GA deficiency in the media. In parallel experiments, these mutants were grown in pure silica sand under greenhouse conditions and were continuously irrigated with ¼ strength Hoagland solution containing various concentrations of calcium and GA3. Similar to the in vitro results, we found that high root zone calcium mitigated some of the GA deficiency symptoms (i.e. shoot growth with longer internodes). Thus, our studies suggest that root zone calcium modifies either the production or action of GA in these mutants. Alternatively calcium perhaps allows the plant to be more effective at lower levels of GA3.