Fig. 3.

The impact of defoliation on NO₃^– uptake in L. perenne. In order to investigate HATS and LATS uptake capacity, plants were grown under low NO₃^– (LN: 0.05 mM) or high NO₃^– (HN: 5 mM), and then defoliated (or left intact). Plants were then exposed for 1 h to either 0.05 mM or 5 mM ¹⁵N-labelled NO₃^– either immediately after defoliation or 48 h after defoliation. During the period of ¹⁵N labelling, the NO₃^– uptake rate was measured. Values are means ±SE (n=5 pools of five plants each). Means were tested for significance using a two-tailed t-test. Asterisks denote significantly different means between intact plants (grey bars) and defoliated plants (black bars) (*P<0.05, **P<0.01, ***P<0.001).