Fungal- and Plant-Specific Gene Markers to Follow the Bean Anthracnose Infection Process and Normalize a Bean Chitinase mRNA Induction. Aline Mahe. Départment de Biologie Moléculaire Végétale, URA CNRS 1128, Bâtiment 430, Université Paris Sud, 91405 Orsay, France. Jeanine Grisvard, and Michel Dron. Départment de Biologie Moléculaire Végétale, URA CNRS 1128, Bâtiment 430, Université Paris Sud, 91405 Orsay, France.. MPMI 5:242-248. Accepted 24 January 1992. Copyright 1992 The American Phytopathological Society.

A bean-specific translation elongation factor (EF-1alpha) and the Aspergillus nidulans actin gene were used to discriminate between bean (Phaseolus vulgaris) and Colletotrichum lindemuthianum RNA contents during a compatible anthracnose interaction. EF-1alpha is constitutively expressed in cotyledonary bean leaves during mock infection. EF-1alpha expression remains stable during the biotrophic phase of the infection process, but it drops rapidly during the necrotrophic phase at the time when the fungus action transcript appears and accumulates. The EF-1alpha gene expression was also used to normalize the induction kinetics of a bean basic chitinase. The results show that the adjustment modified the induction quantitatively by 2.5-fold and shifted the maximal expression by 8 hr when compared to the uncorrected curve. The consequences of these results are discussed in terms of infection processes.