Shrinkage and growth under water stress
As whole plants dehydrated from 0 to -3MPa, peduncles were observed to
shrink by a mean 20% (±4.99%) of their original hydrated area, and
petioles by an average of 46% (±3.39%) (fig. 2). At the same time,
fruit continued to grow, showing a mean increase from original size by
26% (±4.17%). This growth stopped immediately after the vascular
connection with the stem was severed by cutting when stem water
potential reached -1MPa.
The treatment of girdling pedicels was observed to have no effect
(P=0.711) on fruit growth compared with the ungirdled control (fig. 3).
No interaction was observed between treatment (girdled vs ungirdled) and
water potential (P=0.959), indicating fruit of each treatment were
growing in the same way under water stress, despite the phloem of the
girdled fruit being fully disrupted. Both girdled and ungirdled fruit
continued to grow significantly at decreasing water potentials
(4.26e-06***) with girdled fruit growing 4.25% (±0.4%) and ungirdled
fruit growing 4.5% (±0.67%) over the 6 days of plant dehydration.