Claudia Travaglia - Guillermo Balboa - Gabriel Espósito - Herminda Reinoso
Plant Growth Regul DOI 10.1007/s10725-012-9657-7
Received: 11 October 2011 / Accepted: 19 January 2012
Springer Science+Business Media B.V. 2012

Abstract
The aim of this study is to analyze the response of exogenous abscisic acid (ABA) application in plants grown under field conditions in semiarid zones in order to increase maize production. For this, it is necessary to understand the factors, such as the size and capacity of transport system involved in the mobilization and distribution of assimilates. The vascular transport capacity of ABA-treated and control plants was compared in terms of number of vascular bundles, phloem area per bundle, and the proportion of phloem in the ear peduncle of female inflorescences. This study showed that the application of exogenous ABA in field-grown maize under moderate drought allows a greater amount of maize production, an increase in the level of photosynthetic pigments, the carbohydrates remobilization to grain, and the capacity of this transport by an increase in the number of vascular bundles and the phloem area in peduncle. Evidence obtained in this study suggests that ABA could help improve agricultural production in rain-fed crops in which irrigation is not possible. This will allow us to follow a new technological strategy to increase the effective filling of organs during crops in unfavorable water conditions.

Keywords Abscisic acid (ABA)  Maize  Carbohydrates  Phloem  Yield  Water stress