Inducing drought tolerance in lowland rice (Oryza sativa L.) through appliction of exogenous L-proline

Issue Date

8-2011

Abstract

The study evaluated the changes in endogenous proline and the effect of exogenous L-proline application on the growth and grain yield of PSB Rc14 (drought-tolerant) and PSB Rc82 (drought-susceptible) that were exposed under 10-d drought period at early vegetative (EV), panicle initiation (PI) and heading/flowering (Hd/F) stages. Under normal condition, proline contents collected from shoots were relatively high but did not differ between the two cultivars at EV stage, while proline contents were higher in PSB Rc14 than PSB Rc82 at both PI and Hd/F. Proline in PSB Rc14 between normal and drought conditions were similar in content and trend. While PSB Rc82 appeared to be highly sensitive to sudden changes and reduction in the soil water potential (SWP), as rapid accumulation of proline in drought-stressed plants were observed on the first day after water removal, but was not observed under normal condition. Yield reductions due to drought varied with the stage of drought impositions. An actual yield loss of 9-28% in PSB Rc14 and 27-49%in PSB Rc82 were observed due to drought but can be recovered through application of exogenous L-proline. Grain yield of PSB Rc14 were higher in plants applied with L-proline when drought was imposed at EV stage but, had no effect when drought was imposed at PI and Hd/F stages. For PSB Rc82, on the other hand, application of exogenous L-proline stabilized yield when drought was imposed during EV and PI stages, but not at Hd/F stage. In general, yield responses and proline synthesis due to drought stress differed between the drought-tolerant and drought-susceptible cultivars. PSB Rc14, known to be tolerant to drought, had lower yield reductions and synthesized more proline under normal conditions than PSB Rc82, a drought-susceptible cultivar. Further, PSB Rc14 was less responsive to exogenous L-proline applications during drought impositions but was found otherwise for PSB Rc82. Hence, this study opened the opportunity of stabilizing yield of drought-susceptible rice cultivars under drought stress by inducing drought tolerance through exogenous L-proline application.

Source or Periodical Title

Philippine Journal of Crop Science

ISSN

0115-463x

Volume

36

Issue

2

Page

12-19

Document Type

Article

Frequency

tri-quarterly

Physical Description

tables/graphs

Language

English

This document is currently not available here.

Share

COinS