title: Transcriptomic analysis of oxylipin biosynthesis genes and chemical profiling reveal an early induction of jasmonates in chickpea roots under drought stress.
abstract: Drought is one of the major constraints in subtropical agriculture. Therefore improving water stress tolerance is of great importance to breed for drought tolerance in future. The first plant organ sensing dehydration is the root. Aim of the present work was to clarify the potential impact of the phyto-oxylipins pathway on drought tolerance of chickpea (Cicer arietinum), the third important legume crop worldwide. Therefore, we measured the expression of key genes involved in oxylipins metabolism by qPCR on samples from stressed and non-stressed roots of a drought-tolerant and a drought-sensitive chickpea variety using commercially available TaqMan assays. We demonstrate that the drought tolerant variety reacts to drought with sustained and earlier activation of a specific lipoxygenase (Mt-LOX 1) gene, two hydroperoxide lyases (Mt-HPL 1 and Mt-HPL 2), an allene oxide synthase (Mt-AOS), and an oxo-phytodienoate reductase (Mt-OPR). We further show that gene over-expression positively correlates with the levels of major oxylipin metabolites from the AOS branch of the pathway, which finally leads to the synthesis of jasmonates. Higher levels of jasmonic acid (JA), its precursor 12-oxophytodienoic acid (OPDA) and the active form JA-isoleucine (JA-Ile) were especially detected in the root tissues of the tolerant variety, prompting us to assume a role of jasmonates in the early signalling of drought stress in chickpea and its involvement in the tolerance mechanism of the drought-tolerant variety.
authors.affiliation: Institute of Sciences of Food Production C.N.R., Unit of Lecce, via Monteroni, 73100 Lecce, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: De Domenico
authors.forename: Stefania
authors.initials: S
authors.lastname: Bonsegna
authors.forename: Ralf
authors.initials: R
authors.lastname: Horres
authors.forename: Victoria
authors.initials: V
authors.lastname: Pastor
authors.forename: Marco
authors.initials: M
authors.lastname: Taurino
authors.forename: Palmiro
authors.initials: P
authors.lastname: Poltronieri
authors.forename: Muhammad
authors.initials: M
authors.lastname: Imtiaz
authors.forename: Gunter
authors.initials: G
authors.lastname: Kahl
authors.forename: Victor
authors.initials: V
authors.lastname: Flors
authors.forename: Peter
authors.initials: P
authors.lastname: Winter
authors.forename: Angelo
authors.initials: A
authors.lastname: Santino
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D029863:Cicer / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D055864:Droughts; D005231:Fatty Acids, Unsaturated / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D007532:Isoleucine / Q000031:analogs & derivatives / Q000235:genetics / Q000378:metabolism; D008084:Lipoxygenase / Q000235:genetics / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013312:Stress, Physiological / Q000235:genetics*; D059467:Transcriptome; D014867:Water
chemical_list: D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D054883:Oxylipins; D010940:Plant Proteins; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; D014867:Water; C025999:12-oxophytodienoic acid; C011006:jasmonic acid; D008084:Lipoxygenase