Grant Cramer of the University of Nevada is the organizer of the grape genome session held at the annual International Conference on the Status of Plant and Animal Genome Research in San Diego, and at this year’s Jan. 12-16 conference he also gave a presentation at the Jan. 13 grape session.
Cramer’s talk “Early and Late Responses of Grapevine (Vitis vinifera L) to Water Deficit: A Proteomics Perspective” addressed his experiment in water deficit.
“It shows a significant early response in cabernet sauvignon,” Cramer said.
Cramer’s experiment deprived the vines of water for 16 days.
“I think the proteome is telling us a lot more than the transcriptome,” Cramer said. “We didn’t see significant changes in the transcriptome until about eight days into water deficit.”
A proteome is the entire set of proteins expressed at a specific time; a transcriptome is the entire RNA molecular structure.
Cramer measured the shoot tips for both the control plants and the water deficit plants at four, eight, twelve, and sixteen days. Cramer measured photosynthesis as well as growth.
Cramer had several University of Nevada research collaborators, and the project also brought in two scientists from Macquarie University in Australia. The laboratory of Paul Haynes at Macquarie University analyzed the samples Cramer sent.
Haynes’ lab identified 2,227 proteins including 942 which were present in all samples. Haynes’ analysis indicated that 472 proteins were affected by water deficit.
“In some cases the proteins weren’t present,” Cramer said.
Of those 472 altered proteins, significant changes were observed in 159 of those by the fourth day of water deficit, when the roots still had water.
“Growth hasn’t been affected,” Cramer said.
“Most of the photosynthesis proteins went up,” Cramer said. “For me what’s really interesting is this is all happening on Day 4.”