@Article{phyton.2020.08919,
AUTHOR = {Cansu Altuntaş, Rabiye Terzi},
TITLE = {Dithiothreitol and PEG Induced Combined Stress May Affect the Expressions of ABA Aldehyde Oxidase, Sucrose Synthase and Proline Metabolic Genes in Maize Seedlings},
JOURNAL = {Phyton-International Journal of Experimental Botany},
VOLUME = {89},
YEAR = {2020},
NUMBER = {3},
PAGES = {487--495},
URL = {http://www.techscience.com/phyton/v89n3/39405},
ISSN = {1851-5657},
ABSTRACT = {The endoplasmic reticulum (ER) is an organelle in the cell where 
proteins are created and folded. Folding is a very elaborate process that is often 
interrupted by various biotic and abiotic stresses, leading to the formation of 
unfolded and misfolded proteins called ER stress. Dithiothreitol (DTT)-induced 
unfolded protein response (UPR) in endoplasmic reticulum (ER) has been 
recently reported in plants. Also, previous studies demonstrated that treatment 
with polyethylene glycol (PEG<sub>6000</sub>) could stimulate water deficit in crops. 
However, further researches should be conducted to elucidate the molecular 
mechanism of ER stress response and the relationship between water deficiency 
and ER. In this study, we examined the expressions of <i>sucrose synthase</i> (<i>SuS</i>) 
gene, proline metabolic genes and <i>abscisic aldehyde oxidase</i> (<i>AAO3</i>) gene in 
maize seedlings that were subjected to DTT and PEG induced combined stresses 
by using quantitative real-time RT-PCR. Three weeks old detached maize 
seedlings were treated with or without DTT and PEG<sub>6000</sub> for 12 h. The treatment 
with DTT increased about 2-fold the expression of gene encoding proline 
synthesis enzyme, <i>pyrroline-5-carboxylate synthetase</i> (<i>P5CS</i>) but no statistically 
affected the proline catabolism enzyme, <i>proline dehydrogenase</i> (<i>ProDH</i>) in 
comparison with un-treated seedlings. PEG treatment was also up-regulated 
<i>P5CS</i> while it was down-regulated <i>ProDH</i>. The relative expression levels of <i>SuS</i>
and <i>AAO3</i> genes statistically enhanced about 2.5 fold under the DTT-induced ER 
stress. Likewise, the expression levels of <i>SuS</i> and <i>AAO3</i> genes were up-regulated 
in the detached seedlings exposed to PEG-induced water deficit. Conversely, the 
induced gene expressions were down-regulated under the combined stress, the 
DTT-induced ER stress and PEG-induced water deficit in comparison with the 
singular stress responses (DTT or PEG). The results indicated that the expressions 
of genes, related to the synthesis of some signal osmolyte compounds such as 
proline and sucrose can be suppressed when ER stress occurred under water 
deficiency in maize seedlings. The changes in the expressions of genes involved in 
osmolyte and ABA metabolism can be related to ER stress response as well as 
variations in water status.},
DOI = {10.32604/phyton.2020.08919}
}