Gene Expression Profiling during Grape Leaf Development and Senescence by High Density Filters

Leaf photosynthesis in grapevines peaks approximately 30 to 40 days after unfolding and declines thereafter. In order to achieve high quality fruit is important that during the ripening stage the vine's photosynthetic capacity is not diminished due to the leaf senescence. To study grapevine leaf senescence at the molecular level, a transcription profiling analysis during leaf development and senescence was undertaken. A cDNA macroarray containing about 2300 putative unigenes was constructed and hybridized with RNA isolated from Vitis vinifera 'Pinot noir' leaves 7, 88 and 131 days-old. Data analysis focused on genes involved in the photosynthetic process or belonging to the proteinase family. At this stage of leaf senescence two gene categories were mainly affected: the chlorophyll a/b binding (CAB) genes and the cysteine-proteinases genes. While CAB transcripts decrease in their abundance, cysteine-proteinases are activated.