Poster: Photosynthesis
Abs #
352: Trehalose-producing transgenic tobacco plants exhibit increased tolerance and altered photosynthetic capacity to multiple abiotic stresses
|
|
Presenter: |
Hong, Young-Nam , ynhong@snu.ac.kr |
Authors | Hong, Young-Nam (A) Jun, Sung-Soo (A) Yang, Jin Young (A) Choi, Hye Jin (A) Joe, Anna (A) | | Affiliations: |
(A): Seoul National University
|
|
|
Transgenic tobacco plants harboring E. coli TPS (trehalose-6-phosphate synthase) gene (otsA) were generated and were identified by PCR and Northern hybridization. Minute amounts of trehalose (less than 500 mg per g leaf tissue) were detected in transgenic plants while no trehalose was detected in nontransformants. All transgenic plants showed enhanced tolerance against dehydration administered through withholding water supply or PEG-treatment as shown by the maintenance of leaf turgidity. Furthermore, transgenic plants showed improved retention in fresh weight after air-drying or PEG-treatment. However, negative effect on photosynthetic capacity was relieved in transgenic plants. The initial leaf water potential was observed higher in transgenic plants than nontransformants. However, decrease in water potential by dehydration through air-drying or PEG-treatment occurred to a comparable degree in both nontransformants and transgenic plants. Trehalose-producing plants also survived better after sustained growth at 40”ĘC~45”ĘC. After 14 days of growth at 45”ĘC transgenic plants appeared more or less normal in contrast to nontransformants, which underwent extensive leaf chlorosis and necrosis. Furthermore, the photosynthetic capacity (O2 evolution as well as Fv/Fm) and germination efficiency of seed were maintained better after heat-treatment. In addition to dehydration and heat stresses, transgenic plants showed improved tolerance against salinity as well. When plants were grown under 250 mM NaCl, bleaching and chlorosis initiated significantly earlier in nontransformants compared with transgenic plants. Germination was also less inhibited under salinity in transgenic plants. The results suggest that trehalose confers a protection against multiple abiotic stresses.
