Abstract
The effects of drought stress and season on both allocation of photosynthates to stems and leaves and potential for stem rubber synthesis were studied in guayule (Parthenium argentatum Gray USDA line 11604). Two‐year‐old plants grown under field conditions in the Negev desert of Israel were subjected to different irrigation regimes, and water status was assessed by measuring the relative water content (RWC). Undetached plant tips were exposed to a 1 h pulse of 14CO2, followed by a 24 h chase. 14C fixed and translocated to different plants parts and notably 14C incorporation into rubber and resin fractions was determined. The potential of detached branch slices to incorporate [14C]‐acetate into rubber was also studied. A higher percentage of fixed 14C was translocated from shoot tips in winter (28–30%) than in summer (15–18%). The percentage of [14C]‐acctate incorporated into the rubber fraction by stem slices was maximal in winter (20%) and minimal in summer (3–5%) in both cases in the absence of drought stress. In summer the translocation of photosynthates into stems was inversely related to plant RWC, dropping from 18% three days after irrigation to 3% 14 days later, and the potential of stems to synthesise rubber was high under drought conditions and low in well irrigated plants.
Original language | English |
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Pages (from-to) | 45-50 |
Number of pages | 6 |
Journal | Physiologia Plantarum |
Volume | 81 |
Issue number | 1 |
DOIs | |
State | Published - 1 Jan 1991 |
Keywords
- C incorporation
- C translocation
- Parthenium argentatum relative water content resin rubber season
- [C]‐acetate incorporation
- drought stress irrigation
ASJC Scopus subject areas
- Physiology
- Genetics
- Plant Science
- Cell Biology