ABI1 INVOLVEMENT IN POTATO TUBERISATION PROCESS

Potato tuber development is known to be controlled by the hormonal balance between abscisic acid (ABA) and gibberellic acid (GA). In the past few years numerous genes implicated in the hormone signalling pathways have been identified.
Among them, the Abi1 gene seems to be located in the early steps of several ABA signalling pathways.
We have produced transgenic plants expressing abi1-1 and analysed their tuberisation behaviour during in vitro culture in response to ABA alone and in combination with sucrose and ancymidol (a GA synthesis inhibitor). We showed that the transgenic plants exhibit a modified sensitivity to sucrose, ABA and to their combination, as compared to the wild type.
Furthermore, the addition of ancymidol to the tuberisation medium led to a partial restoration of the wild type phenotype.
These results showed the involvement of ABI1 in the ABA signalling pathways during potato tuberisation and pointed to some interaction between the sugar and ABA signalling pathways in this context.
They also provided additional arguments for the control of tuber initiation by the balance between the hormones ABA and GA.

Meeting of the Physiology Section of the European Association for Potato Research

F. Noël, R. Kissen, P. du Jardin

abscisic acid, Solanum tuberosum, tuberisation, ABI1, microtuber, sucrose

https://doi.org/10.17660/ActaHortic.2005.684.20