IN-SITU HYBRIDIZATION OF 2 NODULE-SPECIFIC GENE-PRODUCTS FROM YELLOW LUPIN

We have applied in situ hybridization technique to examine the express ion of two tissue-specific plant genes represented by cDNA clones: pLN -13 and pLN-50 during the symbiosis of Lupinus luteus with Bradyrhizob ium lupini. Both genes are expressed in root nodules and their transcr ipts are restricted to the infected zone of the nodule as revealed wit h S-35- or H-3-labelled antisense RNA probes. The number of grains ove r bacteroid-containing cells after hybridization with H-3-labelled pro bes differed during three tested phases of nodule development: at the 14th, 21st and 28th day after the infection with B. lupini. As control , apical root meristems and segments of root hair zones of uninfected plants were used for incubation with RNA of either sense or antisense orientation preceeded by RNAse A digestion. The data obtained confirm that both genes are organ-specific and reveal their developmentally re gulated expression pattern during the course of root nodule morphogene sis.