1a.Objectives (from AD-416):
The objective of the project is to characterize signaling pathways that regulate tomato and soybean leaf and flower abscission. The signaling mechanisms used in abscission are directly applicable to research on signaling events evoked during nematode infection.
1b.Approach (from AD-416):
The Israeli group will work primarily on tomato whereas ARS will work on soybean. Next Generation Sequencing (NGS) will be performed to identify abscission transcriptomes. Stably transformed plants and VIGS plants will be generated to test functionality of selected genes. Affinity purification of protein complexes followed by tandem mass spectrometry (LC-MS/MS) will be used to identify interacting proteins in signal transduction pathways.
We grew soybean and collected tissue at the base of each leaf where cell separation occurs during leaf drop (abscission zones) and leaf petioles proximal to the separation layer. Abscission zones and petioles were collected at four time intervals after induction of separation by the plant hormone ethylene in three replicate experiments. RNA was extracted from each tissue and 30 samples were submitted for sequence analysis. We recently obtained approximately 2.8 million sequences for each sample. Analysis of the data has begun to identify differential expression in the leaf separation cells.