Molecular biology of actinorhizal nodules: characterization of a metallothionein gene from Casuarina glauca.

OBERTELLO M, AHMADI N, LAPLAZE L, AUGUY F, GUIDERDONI E, BOGUSZ D, FRANCHE C.

Genetic Resources and Biotechnology

Año: 2005; p. 1 - 16

Actinorhizal root nodules result from the interaction between a nitrogen-fixing actinomycete called Frankia and roots of dicotyledonous plants belonging to 8 plant families and 25 genera (Benson and Silvester, 1993). Actinorhizal plants share common features; with the exception of Datisca, which has herbaceous shoots, they are perennial dicots and include woody shrubs and trees such as Alnus (alder), Elaeagnus (autumn olive), Hippophae (sea buckthorn) and Casuarina (beef wood). Most actinorhizal plants are capable of high rates of nitrogen fixation comparable to those found in legumes (Torrey, 1976). In Egypt, a nitrogen-fixing potential of 288 kg N.ha-1 has been reported for Casuarina (Diem and Dommergues, 1990). As a consequence, these plants are able to grow in poor and disturbed soils and are important elements in plant communities worldwide. In addition, some actinorhizal species can grow well under a range of environmental stresses such as high salinity, heavy metal and extreme pH (Dawson, 1990). This facility for adaptation has drawn great interest to actinorhizal plants, particularly to several species of Casuarinaceae, which can be used for fuelwood production, agroforestry, and land reclamation in the tropics and subtropics (Diem and Dommergues, 1990).