Factors Affecting the Expression of 9,13-Hydroperoxide Lyase in Cucumbers
Location
CSU 253/4/5
Start Date
5-4-2010 10:00 AM
End Date
5-4-2010 12:00 PM
Student's Major
Chemistry and Geology
Student's College
Science, Engineering and Technology
Mentor's Name
James Rife
Mentor's Department
Chemistry and Geology
Mentor's College
Science, Engineering and Technology
Description
Cucumbers produce 6 and 9 carbon-long aldehydes which not only are important flavor and fragrance compounds but may also play roles in the plant’s defense against pathogens. These aldehydes are produced from polyunsaturated fatty acids in two steps. Lipoxygenases convert the fatty acids into hydroperoxides by addition of molecular oxygen to 1,4-pentadiene systems, which are then cleaved into the aldehydes by Hydroperoxide Lyases. Cucumbers apparently have an unique 9,13-Hydroperoxide Lyase (9,13-HPLase) that can cleave hydroperoxides at both the 9 and 13 positions on the fatty acid chain (Matsui, et al.
Phytochemistry 67, 649-657, 2006). In previous studies, Ranginwala (JUR, 2009) used Real Time Polymerase Chain Reaction (Q-PCR) to confirm that wounding enhanced expression of 9,13-HPLase. Preliminary results suggested that wounding might elicit a systemic enhancement of 9,13-HPLase expression. In the current study, the Q-PCR procedure has been refined to elucidate whether wounding truly caused systemic enhancement of 9,13-HPLase expression rather than a localized effect. Cucumber plants were grown, and control and experimental samples were obtained from cotyledons as well as from primary and secondary leaves. Plants were treated with methyl jasmonate and norbornadiene to explore the mechanism of wound enhanced 9,13-HPLase expression. RNA was extracted from the samples and reverse transcription was used to make cDNA copies of the mRNA transcripts. The relative numbers of the cDNA were measured using Q-PCR. Preliminary studies have shown that 9,13-HPLase expression decreased in newer leaves compared to older leaves.
Factors Affecting the Expression of 9,13-Hydroperoxide Lyase in Cucumbers
CSU 253/4/5
Cucumbers produce 6 and 9 carbon-long aldehydes which not only are important flavor and fragrance compounds but may also play roles in the plant’s defense against pathogens. These aldehydes are produced from polyunsaturated fatty acids in two steps. Lipoxygenases convert the fatty acids into hydroperoxides by addition of molecular oxygen to 1,4-pentadiene systems, which are then cleaved into the aldehydes by Hydroperoxide Lyases. Cucumbers apparently have an unique 9,13-Hydroperoxide Lyase (9,13-HPLase) that can cleave hydroperoxides at both the 9 and 13 positions on the fatty acid chain (Matsui, et al.
Phytochemistry 67, 649-657, 2006). In previous studies, Ranginwala (JUR, 2009) used Real Time Polymerase Chain Reaction (Q-PCR) to confirm that wounding enhanced expression of 9,13-HPLase. Preliminary results suggested that wounding might elicit a systemic enhancement of 9,13-HPLase expression. In the current study, the Q-PCR procedure has been refined to elucidate whether wounding truly caused systemic enhancement of 9,13-HPLase expression rather than a localized effect. Cucumber plants were grown, and control and experimental samples were obtained from cotyledons as well as from primary and secondary leaves. Plants were treated with methyl jasmonate and norbornadiene to explore the mechanism of wound enhanced 9,13-HPLase expression. RNA was extracted from the samples and reverse transcription was used to make cDNA copies of the mRNA transcripts. The relative numbers of the cDNA were measured using Q-PCR. Preliminary studies have shown that 9,13-HPLase expression decreased in newer leaves compared to older leaves.
Recommended Citation
KC, Ashok Singh and Samee M. Ranginwala. "Factors Affecting the Expression of 9,13-Hydroperoxide Lyase in Cucumbers." Undergraduate Research Symposium, Mankato, MN, April 5, 2010.
https://cornerstone.lib.mnsu.edu/urs/2010/poster-session-A/25
