The characterisation and modulation of homeobox genes may represent a powerful tool to manipulate life cycle and development of fruit trees. In plants, some members of homeotic genes (knotted genes) have been identified as responsible for the very early signalling that turns on the process of leaf genesis in meristems. Other knotted-like genes have been found not to be meristem specific but differentially expressed in distinct tissues. A leading hypothesis proposes that knotted-like genes control cell vegetative identity and activate the signals to determine cell fate. In our laboratory, two distinct cDNA clones (KNAPE1 and KNAPE2) were amplified by RT-PCR starting from RNA of apical tips of peach shoots (Prunus persica L. Batsch). KNAPE1 and KNAPE2 shared a very high similarity to plant homeotic genes, fallingl into the knotted 1 class, but diverged one from the other (52% deduced amino acidic homology). In Southern hybridisation, distinct patterns for each clone suggested that each gene was present in one or two copies in peach genome. In Northern analyses, signals of KNAPE1 were only detected at a low level in differentiated buds, whereas KNAPE2 messages were equally signalled in vegetative tissues of juvenile and adult plants except for stamens, petals and the roots in which no signal was observed. KNAPE2 messages were specifically localised in parenchima cells of forming and fully expanded leaves. KNAPE1 messages were localised in the triple bud meristems at very early stages of development, that is when the side buds (flower fate) started to form at the leaf axillary position and the central bud (vegetative fate) was already differentiated. A distinct localisation pattern appeared to mark the two bud types and it will be presented and discussed.
"Isolation and characterisation of two homeobox genes belonging to the Knotted-1 class in peach (Prunus persica L. Batsch)".
Giannino D;Mele G;Frugis G;Mariotti D
2000
Abstract
The characterisation and modulation of homeobox genes may represent a powerful tool to manipulate life cycle and development of fruit trees. In plants, some members of homeotic genes (knotted genes) have been identified as responsible for the very early signalling that turns on the process of leaf genesis in meristems. Other knotted-like genes have been found not to be meristem specific but differentially expressed in distinct tissues. A leading hypothesis proposes that knotted-like genes control cell vegetative identity and activate the signals to determine cell fate. In our laboratory, two distinct cDNA clones (KNAPE1 and KNAPE2) were amplified by RT-PCR starting from RNA of apical tips of peach shoots (Prunus persica L. Batsch). KNAPE1 and KNAPE2 shared a very high similarity to plant homeotic genes, fallingl into the knotted 1 class, but diverged one from the other (52% deduced amino acidic homology). In Southern hybridisation, distinct patterns for each clone suggested that each gene was present in one or two copies in peach genome. In Northern analyses, signals of KNAPE1 were only detected at a low level in differentiated buds, whereas KNAPE2 messages were equally signalled in vegetative tissues of juvenile and adult plants except for stamens, petals and the roots in which no signal was observed. KNAPE2 messages were specifically localised in parenchima cells of forming and fully expanded leaves. KNAPE1 messages were localised in the triple bud meristems at very early stages of development, that is when the side buds (flower fate) started to form at the leaf axillary position and the central bud (vegetative fate) was already differentiated. A distinct localisation pattern appeared to mark the two bud types and it will be presented and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
