c6.2.5 – Molecular and ecophysiological approach to identify genes controlling salinity tolerance in Populus alba L.

Beritognolo I* (1), Brilli F (2), Gaudet M (1), Kuzminsky E (1), Loreto F (2), Paolucci I (1), Sabatti M (1), Salani F (1), Scarascia Mugnozza G (1+2), Valentini R (1)

(1) DISAFRI, Università degli Studi della Tuscia, Viterbo; (2) CNR IBAF, Monterotondo (RM)
Collocazione: c6.2.5 – Tipo Comunicazione: Presentazione orale
6° Congresso SISEF *
Sessione 2: “Sessione 2: Fattori di stress e strategie di mitigazione” *

Contatto: Isacco Beritognolo (isacco@unitus.it)

Abstract: Soil salinity is an increasing problem in the Mediterranean region because of wrong irrigation management and global climate changes. Populus alba is an interesting agroforestry species for its fast growth and adaptation to the Mediterranean environment. Populus alba native germplasm represents an unexploited genetic resource to improve stress tolerance. The objective of this study is to characterise the response to salt stress in two divergent Populus alba genotypes collected at different latitudes and showing different response to salinity. Rooted cuttings from both genotypes were grown in sand pots and irrigated with a half strength Hoagland’s nutrient solution. A shock salt stress was applied by adding sodium chloride (200 mM) to the irrigation solution. Leaves were collected three, 27, and 75 hours after starting the stress treatment to analyse mineral uptake and transcriptome regulation. After one day of treatment, the mineral analyses revealed a strong accumulation of sodium in leaves of salt stressed plants and the concentration increased over time. Experimental data indicated that both hyper-osmotic and ionic stress was induced in the leaves of both genotypes. The transcriptome regulation was investigated by cDNA microarrays that contained about 8000 transcript sequences selected from Populus euphratica cDNA libraries. The number of stress-regulated genes increased from three to 75 hours of stress. A large number of genes were found to be down-regulated in both genotypes, whereas few genes were regulated in only one genotype. Cluster analysis revealed two groups of genes that responded to stress in an opposite manner. These genes represent candidates to explain the genetic variability of salinity tolerance.

Citazione: Beritognolo I , Brilli F , Gaudet M , Kuzminsky E , Loreto F , Paolucci I , Sabatti M , Salani F , Scarascia Mugnozza G +, Valentini R (2007). Molecular and ecophysiological approach to identify genes controlling salinity tolerance in Populus alba L. . 6° Congresso Nazionale SISEF, Arezzo, 25 – 27 Set 2007, Contributo no. #c6.2.5