ARS | Publication request: TEMPERATURE SWITCHING OF EARLY ENVIRONMENTAL LIGHT EFFECTS ON PIGMENTS AND LEAF MORPHOLOGY

Submitted to: United States Japan Natural Resources Protein Panel
Publication Type: Proceedings
Publication Acceptance Date: November 15, 1995
Publication Date: N/A

Technical Abstract: Lettuce (Lactuca sativa) seedlings were grown under 150 umol m**-2 s**-1 each of blue, red, and white light for 3 weeks at 25 deg C, 30 deg C, and 35 deg C. At 10 days, while the first leaf was still expanding, plantlets were switched from blue to red light or from red to blue light and allowed to grow until the fifth leaf was newly emerged. All leaves were collected and analyzed for leaf size, weight, and for chloroplast pigment content. Results of these analysis indicate that blue light given during the early stages of development is effective at fixing a pattern of leaf morphology and pigment content even after the leaves have been switched to red light and allowed to grow for the remaining 2 weeks. Red light during the first 10 days, however, does not fix a pattern of development in plants switched to blue light. The degree of early environmental fixing of developmental pattern by blue light is strongly influenced by temperature and is weak at 25 deg C, stronger at 35 deg C, and strongest at 30 deg C. These results suggest that developmental patterns in a mature leaf can be fixed by early environment.