Expression of MsLEC1- and MsLEC2-antisense genes in alfalfa plant lines causes severe embryogenic, developmental and reproductive abnormalities

Although it has been proposed that plant lectins play a number of roles, th e function of these proteins in normal plant growth and development has bee n unclear. To analyze the functions of putative alfalfa lectin genes, lines of transgenic alfalfa plants expressing approximately half of the open rea ding frame of MsLEC1 or MsLEC2, in the antisense or sense orientation, were established and analyzed. The antisense plants displayed severe abnormalit ies in embryogenesis, and both vegetative and reproductive development were perturbed. Some differences were observed between MsLEC1- and MsLEC2-antis ense plants, and abnormalities were especially severe during the early stag es of development in both the primary and secondary transgenic generations. In contrast, vector-control and sense-transgene plants exhibited normal gr owth and development. MsLEC1 and MsLEC2 mRNA accumulation levels were reduc ed in cognate antisense plants, especially during the later stages of embry ogenesis, but also tended to be low in MsLEC1 sense-transgene plants. Howev er, correlated with the phenotypic abnormalities observed in the MsLEC1-ant isense plants was the specific reduction in the accumulation of a candidate MsLEC1 protein. Our results suggest that the MsLEC1 and MsLEC2 gene produc ts, in addition to being important for embryogenesis, are required througho ut alfalfa development.