Conference Paper ABSCISSION REGULATORY NETWORKS: A TRANSCRIPTOMIC ANALYSIS USING NGS AND A NOVEL TOMATO FLOWER AND LEAF ABSCISSION ZONE CUSTOMIZED MICROARRAY Srivignesh Sundaresan Joseph Riov Bettina Kochanek Raja Mugasimangalam Shomon Meir Conference: The 7th Congress of the Federation of the Israel Societies for Experimental Biology February 10-13, 2014 , Eilat, At Eilat , Israel, Volume: 7 th FIESB, ABSTRACT Abscission is a highly regulated process of cell separation, by which plants are able to shed their organs. Abscission is initiated by decreased auxin activity and increased ethylene production, as well as increased sensitivity to ethylene in the abscission zone (AZ) cells. In the present study we used a new approach to identify novel transcripts in tomato (Solanum lycopersicum) flower and leaf AZs (FAZ and LAZ, respectively) at various stages of abscission, by designing a customized AZ-specific microarray chip. This chip was based on 176,026 probes, including transcripts from the Next Generation Sequencing (NGS) of RNA isolated from tomato AZs at various times during abscission and public domain data bases (NCBI-RefSeq, SOL genomics network). Both sense and antisense probes were included for all the transcripts. The results are deposited at the following databases: AMADID ID - 043310; NCBI GEO ID - GSE45355 (for FAZ), and GSE45356 (for LAZ). As expected, several auxin-related genes, such as Aux/IAA, PIN, and Small Auxin-Up RNA (SAUR), shared a common pattern of down regulation during abscission, while some other genes of these families were transiently up-regulated. Several ethylene biosynthesis genes, such as 1-Amino-Cyclopropane-1-Carboxylic acid (ACC) Synthase (ACS) and ACC Oxidase (ACO), abscission-related genes such as Cellulases and Pathogenesis-Related (PR), and transcription factors genes were up-regulated, while most of the Ethylene Response Factor (ERF) families were down-regulated during abscission. The analyses revealed that the FAZ and LAZ share both similar and different expression patterns in the execution of abscission. We observed also a high occurrence (5,000 probes) of natural antisense transcripts (NAT) in both the FAZ and LAZ, indicating their significant involvement in the abscission process. Our study provides new insights into regulation of the early abscission events. Based on these data, a model for abscission regulatory networks in the FAZ and LAZ will be presented.
Posted on: Fri, 24 Oct 2014 04:59:17 +0000