E. Vanderknaap et al., EXPRESSION OF AN ORTHOLOG OF REPLICATION PROTEIN A1 (RPA1) IS INDUCEDBY GIBBERELLIN IN DEEP-WATER RICE, Proceedings of the National Academy of Sciences of the United Statesof America, 94(18), 1997, pp. 9979-9983
Internodes of deepwater rice are induced to grow rapidly when plants b
ecome submerged. This adaptation enables deepwater rice to keep part o
f its foliage above the rising flood waters during the monsoon season
and to avoid drowning. This growth response is, ultimately, elicited b
y the plant hormone gibberellin (GA),The primary target tissue for GA
action is the intercalary meristem of the internode. Using differentia
l display of mRNA, we have isolated a number of genes whose expression
in the intercalary meristem is regulated by GA. The product of one of
these genes was identified as an ortholog of replication protein A1 (
RPA1). RPA is a heterotrimeric protein involved in DNA replication, re
combination, and repair and also in regulation of transcription. A chi
meric construct, in which the single-stranded DNA-binding domain of ri
ce RPA1 was spliced into the corresponding region of yeast RPA1, was a
ble to complement a yeast rpa1 mutant. The transcript level of rice RP
A1 is high in tissues containing dividing cells. RPA1 mRNA levels incr
ease rapidly in the intercalary meristem during submergence and treatm
ent with GA before the increase in the level of histone H3 mRNA, a mar
ker for DNA replication.