Poster: Vegetative Development

Abs # 451: Cloning and characterization of leaf senescence associated genes in maize plants

Presenter:	Dai, Ziyu , ziyu.dai@pnl.gov
Authors	Dai, Ziyu  (A)   Hooker, Brian S (A)   Lasure, Linda L. (A)
Affiliations:	(A): Pacific Northwest National Laboratory

Senescence genes are up-regulated during plant senescence and many have been implicated in encoding enzymes involved in the metabolisms of senescence tissues. To identify senescence associated genes in maize leaves, senescence was induced by incubating the full-expanded detached leaves in the dark for various time periods. Senescence up-regulated cDNA clones were obtained by PCR-based suppression subtractive hybridization (SSH). The SSH clones were randomly selected for differential screening and DNA sequencing analyses. Thirty SSH clones identified were up-regulated in the dark-induced senescence leaves. Fourteen of 30 clones were found to be associated with dark-induced or natural leaf senescence. Other sixteen SSH clones were unknown. The RNA-gel blot analysis confirmed that the transcription of the 10 selected SSH clones in the detached leaves was dramatically enhanced after one day incubation in the dark. The effects of leaf ages, methyl jasmonic acid, and abscisic acid on the transcription of the 10 selected SSH clones are being examined. The possible physiological roles of those senescence associated genes during maize leaf senescence will be discussed.