Publications (2)5.65 Total impact
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Article: Expression analysis of aquaporins from desert truffle mycorrhizal symbiosis reveals a fine-tuned regulation under drought.
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ABSTRACT: We have performed the isolation, functional characterization and expression analysis of aquaporins in roots and leaves of Helianthemum almeriense, in order to evaluate their roles in tolerance to water deficit. Five cDNAs, named HaPIP1;1, HaPIP1;2, HaPIP2;1, HaPIP2;2 and HaTIP1;1, were isolated from H. almeriense. A phylogenetic analysis of deduced proteins confirmed that they belong to the water channel proteins family. The HaPIP1;1, HaPIP2;1 and HaTIP1;1 genes encode functional water channel proteins, as indicated by expression assays in Saccharomyces cerevisiae, showing divergent roles in the transport of water, CO2 and NH3. The expression patterns of the genes isolated from H. almeriense, and of a previously described gene from Terfezia claveryi (TcAQP1), were analyzed in mycorrhizal and non-mycorrhizal plants cultivated under well-watered or drought stress conditions. Some of the studied aquaporins were subjected to fine-tuned expression only under drought stress conditions. A beneficial effect on plant physiological parameters was observed in mycorrhizal plants with respect to non-mycorrhizal ones. Moreover, stress induced a change in the mycorrhizal type formed, which was more intracellular under drought stress. The combination of a high intracellular colonization, together with the fine-tuned expression of AQPs, could result in a morpho-physiological adaptation of this symbiosis to drought conditions.Molecular Plant-Microbe Interactions 05/2013; · 4.43 Impact Factor -
Article: Physiological parameters of desert truffle mycorrhizal Helianthemun almeriense plants cultivated in orchards under water deficit conditions
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ABSTRACT: Physiological parameters of mycorrhizal symbiosis by Helianthemum almeriense and Terfezia claveryi in orchards were characterized under water deficit conditions. Our orchard included 40 mycorrhizal and 40 nonmycorrhizal plants. Only mycorrhizal plants survived at the beginning of the experimental period, indicating dependency on fungal symbionts in roots for survival. Drought stress significantly affected the mycorrhizal colonization percentage which was 70% in nonirrigated mycorrhizal and 48% in irrigated mycorrhizal plants. No significant differences in plant growth were observed between nonirrigated and irrigated mycorrhizal plants before and after drought stress. Stomatal conductance was more sensitive to water stress than shoot water potential. It decreased more than two-fold under drought-stress compared to control mycorrhizal plants under irrigation/light saturating conditions, indicating important stomatal closure with water deficit. Plants’ water use efficiency improved with drought with stomatal conductance values below 0.3mol m−2 s−1. The ability to maintain open stomata and photosynthesis under drought increased carbon supply for growth, and ascocarp fruiting which requires current photosynthates. Basically, H. almeriense shows a conservative water use strategy based mainly on avoiding drought stress by reducing stomatal conductance as soil water potential decreases and atmospheric conditions dry. The results show that mycorrhizal H. almeriense plants maintain good physiological parameters with low soil matric potentials, thus making them an alternative agricultural crop in arid/semi-arid areas. KeywordsDesert truffle cultivation-Drought stress avoidance-EctendomycorrhizaSymbiosis 04/2012; 52(2):133-139. · 1.21 Impact Factor
