Low temperature storage induces acid invertase in potato tubers (Solanum tuberosum)

We have studied the accumulation of acid invertase isozymes and gene transcripts in potato (Solanum tuberosum cv. Russet Burbank) tubers stored at 10 degrees C or 1 degrees C. Northern blot analysis using a cDNA probe to vacuolar invertase showed that the invertase transcript does not accumulate in tubers stored at 10 degrees C. However, in tubers stored at 1 degrees C the invertase transcript level increases markedly within 7 days. The accumulation of acid invertase transcripts was found coincident with an increase in invertase activity, mainly the isoform with a pi value of 5.37. Southern blot analysis indicated that the vacuolar acid invertase gene is probably present in one or two copies per haploid genome.