Identification of Possible Mechanisms of Chickpea ( Cicer arietinum L.) Drought Tolerance Using cDNA-AFLP

Abstract

Drought sensitivity is considered as a major concer n for chickpea ( C. arietinum ) seed production. Determination of drought adaptation mec hanisms is an essential constituent of this crop breeding programs. With this purpose, the present research was conducted to distinguish the molecular basis of chickpea drought tolerance using cDNA-AFLP approach. The expression profile was compared betwe en drought tolerant (ICCV2 and FLIP9855C) and susceptible lines (ILC3279) of chick pea under three drought treatments including well-watered, intermediate, and severe st ress; where soil water content was kept at 85–90% , 55–60% , and 25–30% of Field capacity, respectively. Totally, 295 tran script- derived fragments (TDFs) were visualized. Among the differentially expressed TDFs, 72 TDFs were sequenced. Sequenced cDNAs were categoriz ed in different functional groups involved in macromolecules metabolism, cellular tra nsport, signal transduction, transcriptional regulation, cell division and energ y production. Based on the results, ribosomal protein S8, mitochondrial chaperone, prot eases, hydrolases, UDP -glucuronic acid decarboylase, 2-hydroxyisoflavanone dehydratas e, NADPH dehydrogenase, chloride channels, calmodulin, ABC transporter, histone deac etylase and factors involved in chloroplast division were among genes that were aff ected by drought stress. Similarity search in data base showed that cell wall elasticit y, isoflavonoids, maintenance of structure and function of proteins through increase in expression of mitochondrial chaperones, programed cell death, and remobilizatio n of storage material from leaves to seeds were among mechanisms that distinguished diff erences between drought tolerant and drought susceptible lines. Keywords : Drought stress, cDNA- amplified fragments length polymorphism, Transcript derived fragments (TDFs), Gene expression.