Table IV.

Changes in total pool sizes of α-branch compared with β-branch carotenoids during acclimation of sun leaves to shade and shade leaves to sun

The α-branch carotenoid pool [α(C+X)] was calculated as the sum of the means of the α-C+Lx+L pools. The β-branch carotenoid pool [β(C+X)] is the sum of the means of the β-C+V+A+Z+N pools. The differences (Δ) in pool size were assessed by comparing the amounts of pigments at the beginning and end of the respective sun and shade periods. Negative values indicate decreases in total pool size.

Treatment		Δα(C+X)	Δβ(C+X)	Δα/Δβ(C+X)
		mmol mol−1 chlorophyll
Shade acclimated →	sun (short term)
Young (y1)a	8 h of sun	36.5	41.6	0.9
	16 h of shade	40.0	46.2	0.9
Young (y2)a	8 h of sun	21.1	20.6	1.0
	16 h of shade	44.8	46.7	1.0
Matureb	6–8 h of sun	10.4 ± 1.8	9.1 ± 2.2	1.1
	16–18 h of shade	14.6 ± 1.7	13.6 ± 2.2	1.1
Shade acclimated →	sun (long term)
Youngc	19 d of sun	41.2	72.6	0.6
Maturec	19 d of sun	52.2	124.0	0.4
Sun acclimated →	shade (short term)
Youngd	8 h of sun	9.7	8.4	1.2
	16 h of shade	33.5	51.0	0.7
Matured	6–8 h of sun	19.3	14.4	1.3
	16 h of shade	16.3	14.8	1.1
Sun acclimated →	shade (long term)
Younge	43 d of shade	−35.6	−31.4	1.2
Maturee	43 d of shade	−36.3	−35.3	1.0

^aData from experiment 2, first diel.

^bData from experiments 1, 4, and 5, first diels (n = 3).

^cData from experiment 5, days 0 to 19.

^dData from experiment 3, first diel.

^eData from experiment 3, days 0 to 43.