Effects of exogenous abscisic acid (ABA) on cucumber seedling leaf carbohydrate metabolism under low temperature

Abstract

Seedlings with four true leaves of cucumbers (Cucumis sativus L.), Guonong No.25 (a coldtolerant cultivar) and Guonong No.41 (a cold sensitive cultivar), were grown under normal or low temperature conditions: 25°C/18°C or 15°C/8°C (day/night). The seedlings of Guonong No.25 under low temperature were also treated with or without exogenous ABA. The purpose of our study was to find out the effects of low temperature and exogenous ABA application on the carbohydrate metabolism in the cucumber plants. Time course changes of carbohydrate contents and activities of stachyose synthase and alkaline a-galactosidase in the seedling leaves were investigated after the treatment. Our results show that compared to the seedlings under temperatures of 25°C/18°C, the seedlings of the both tested genotypes under 15°C/8°C (day/night) have significantly higher contents of all measured soluble carbohydrates. Significant difference in stachyose synthase activity is observed between the two genotypes under normal temperature or low temperature. Under normal temperature, leaf stachyose synthase activity in Guonong No.41 is higher than that in Guonong No.25. The stachyose synthase activity of Guonong No.41 decreases sharply under low temperature, but that of Guonong No.25 increases 3 days after treatment and then decreases to the original level. In contrast, there is no significant genotypic difference in alkaline a-galactosidase activity. Additionally, compared to the control seedlings treated with 0 lM ABA, the seedlings treated with 50 and 150 lM ABA accumulate substantial amounts of all tested soluble carbohydrates except galactose whereas 250 lM ABA treated seedlings show decreased levels of all these soluble carbohydrates. Stachyose synthase activity increases significantly upon 50 and 150 lM ABA treatments.

Epigenetic map and genetic map basis of complex traits in cassava population

“…We detected 260 genes with repeatable cold-tolerance QTLs (reCT-QTLGs) and 301 genes with repeatable quality and yield QTLs (reQY-QTLGs) in these pathways (Tables S9 and S10). Phytohormones play important roles in the adjustment to adapt to the environmental stresses222829. Consistent with these findings, ABA biosynthesis reCT-QTLG ( nine-cis-epoxycarotenoid dioxygenase 3, NCED3 ), jasmonate biosynthesis reCT-QTLG ( OPDA reductase 3, OPR3 ) and ethylene biosynthesis reCT-QTLGs (1-aminocyclopropane-1-carboxylate synthase 7 and ethylene signal DNA binding/transcription factor) were detected in the hormone synthesis and metabolism pathway (Fig.…”

Plant Physiological, Morphological and Yield-Related Responses to Night Temperature Changes across Different Species and Plant Functional Types

“…Low temperature is one of the major environmental factors impacting plant growth, development and ecological distribution (Allen and Ort, 2001). A variety of crops from tropical and sub-tropical regions, such as maize, tomato, cucumber, and mango, are sensitive to cold when cultivated in temperate environments (Jones and Ort, 1998; Allen and Ort, 2001; Meng et al, 2008). As people have begun introducing plants from warm climates into cool climates, it has become important to understand the effects of LNT stress, which needs substantially more research.…”

Effects of exogenous abscisic acid pre-treatment of cucumber (Cucumis sativus) seeds on seedling growth and water-stress tolerance

“…Abscisic acid (ABA) and indole-3-acetic acid (IAA) are involved in the development of defence responses during adaptation to drought (Pustovoitova et al 2004). In our laboratory, we found that exogenous ABA could improve tolerance to low temperature (Meng et al 2008); pre-treatment of seeds with ABA is much easier than spraying ABA on seedlings. Unfortunately, no detailed study has been conducted to describe how seedlings grown from ABA pre-treated cucumber seeds are affected.…”