Plant Molecular Biology 41: 371–386, 1999.
© 1999 Kluwer Academic Publishers. Printed in the Netherlands.
Pollination, wounding and jasmonate treatments induce the expression of
a developmentally regulated pistil dioxygenase at a distance, in the ovary,
in the wild potato Solanum chacoense Bitt.
Sylviane Lantin, Martin O’Brien and Daniel P. Matton
Institut de Recherche en Biologie V´eg´etale, D´epartement de Sciences Biologiques, Universit´edeMontr´eal,
Montr´eal, Qu´ebec, Canada, H1X 2B2 (
author for correspondence)
Received 3 May 1999; accepted in revised form 19 August 1999
Key words: 2-oxoglutarate-dependent dioxygenase, fertilization-induced gene, plant reproduction, pollination-
induced gene, secondary metabolites, wild potato, wound-induced gene
Pollination and fertilization trigger unique developmental programs leading to embryogenesis, ovary maturation
and seed set. Pistil tissues are actively involved in pollen tube growth and respond to the presence of the growing
pollen tubes by modulating the expression of speciﬁc genes. Using subtractive hybridization to isolate genes
involved in pollen-pistil interactions and fertilization, we have isolated a pollination- and fertilization-induced
dioxygenase which is predominantly expressed in the pistil. In situ hybridization analyses revealed that the SPP2
dioxygenase (Solanum pollinated pistil) from the self-incompatible wild potato Solanum chacoense Bitt. is also
developmentally regulated, with mRNA levels gradually regressing from the tip of the style towards the ovary
during pistil development. At maturity, the upper limit of SPP2 transcript distribution coincided with the abscission
zone of the style and SPP2 dioxygenase expression in ovaries coincided with the fertilization receptivity period of
the ﬂower. Pollination, as well as wounding of the style, induced an increase in SPP2 mRNA steady-state levels at
a distance, in the ovary. Treatments with stress hormones including methyl jasmonate, jasmonic acid and salicylic
acid mimicked the wound response and also induced SPP2 transcripts in the ovary. The SPP2 dioxygenase could be
involved in the biosynthesis of deterrent alkaloids in reproductive tissues or in generating chemical signals involved
in pollen tube guidance.
Abbreviations: AA, arachidonic acid; ABA, abscisic acid; DPA, days after anthesis; DPP, days after pollination;
DPW, days after wounding; JA, jasmonic acid; MeJA, methyl jasmonate; SA, salicylic acid.
Sexual reproduction in ﬂowering plants involves in-
timate interactions between the growing pollen tube
and the female reproductive structure, the pistil. Af-
ter landing on the stigma surface where the pollen
grains adhere and hydrate, the pollen grains grow a
protruding tube which carries the sperm cells through
the transmitting tissue of the style towards the ovary.
The two sperm nuclei carried at the tip of the growing
The nucleotide sequence data reported will appear in the Gen-
Bank, EMBL and DDBJ Nucleotide Sequence Databases under the
accession number AF104925 (SPP2 dioxygenase cDNA).
pollen tube enter the ovules through the micropyle and
fuse with the egg and the central cell nuclei, forming
the zygote and the endosperm (Russell, 1992).
During pollen tube growth, the pistil plays an ac-
tive role in pollen tube guidance and nourishment
(Cheung, 1996). Furthermore, in self-incompatible
species, such as Solanum chacoense, the pistil acts
as a sieve, blocking pollen tubes carrying an S-allele
identical to the ones expressed in the style from reach-
ing the ovary (Matton et al., 1998). Although many
genes involved in male and female gametophyte de-
velopment have been characterized in recent years
(Raghavan, 1997), less attention has been devoted to