. 2019 Oct 23;42(1):44–51. doi: 10.1016/j.pld.2019.09.004

Table 2.

Effects of ambient CO₂ concentration (400 μmol mol⁻¹) and elevated CO₂ concentration (800 μmol mol⁻¹) treatments on sugars, proline, specific leaf area (SLA), and leaf and pod numbers of soybean plants at different growth stages. The values in the same column with different letters are significantly different (P < 0.05). Data are mean ± S.D. (n = 5, 6, 9, or 10); experiments were repeated three times. SLA, specific leaf area; FW, fresh weight; DW, dry weight. V1, first fully developed trifoliate leaves; R2, leaves from full flowering soybeans; R4, leaves from full pod stage of soybean.

Growth stage	CO₂ treatment	Sugars (mg/g FW)	Proline (μg/g FW)	SLA (mg DW/cm²)
V1	Ambient	7.66 ± 0.55^c	162.33 ± 8.72^b	2.12 ± 0.22^d
V1	Elevated	7.95 ± 0.53^c	141.56 ± 9.12^c	2.39 ± 0.51^cd
R2	Ambient	9.99 ± 0.21^b	176.60 ± 9.29^b	3.02 ± 0.51^ab
R2	Elevated	9.49 ± 0.42^b	132.23 ± 7.92^c	2.84 ± 0.43^bc
R4	Ambient	11.53 ± 0.67^a	234.67 ± 14.31^a	3.27 ± 0.26^ab
R4	Elevated	10.18 ± 0.64^b	224.84 ± 17.46^a	3.40 ± 0.28^a
		Leaf area (cm²)	No. trifoliate leaves	No. pods
R4	Ambient	40.81 ± 3.76^a	11.82 ± 1.78^b	13.10 ± 1.07^b
R4	Elevated	39.98 ± 5.45^a	14.30 ± 1.33^a	15.00 ± 1.63^a