AtSIP1;1 and HsAQP5 transcript levels. mRNA levels of induced single copy HsAQP5- (HsAQP5:100:5) and AtSIP1;1- (AtSIP1;1:100:2) clones. Triplicate cultures were analysed by qPCR. Values are given as the average relative ratio between aquaporin mRNA and actin mRNA. AtSIP1;1 mRNA levels are low as compared with the AQP5 transcript levels but still substantially higher than these of the reference (actin).