Table 5.

Incorporation of sucrose into various biopolymer pools of normoxic (aerated), hypoxic (3% O₂), and anoxic (N₂) rice coleoptiles using a [¹⁴C] sucrose tracer Three-day-old seedlings (10–15) were placed into growth solution supplemented with 50 mM sucrose and 10 nCi ml⁻¹ [¹⁴C] sucrose. The labelling period was 4 h. Coleoptiles were frozen in liquid N₂ then freeze-dried. Free amino acids, extractable proteins, lipids, nucleic acids, and cell walls were extracted as described in the Materials and methods. ¹⁴C activity was measured and converted to quantities of sucrose for each sample. Rates of incorporation into each pool were determined. Rates are in nmol (sucrose incorporated) g⁻¹ (FW) min⁻¹. Data are mean and SEM (n=3). Statistically different data across treatments (Tukey–Kramer, α=0.05) are indicated by different letters.

Biopolymer pool	Normoxic	Hypoxic	Anoxic
Free amino acids	42.4±3.7 a	27.9±1.0 b	4.8±0.8 c
Extractable protein	35.4±4.0 a	19.9±2.2 b	4.4±0.9 c
Lipids	3.8±1.0 a	2.7±0.7 b	2.4±0.1 b
Nucleic acids	3.8±1.0 a	1.7±0.3 b	2.2±0.3 b
Cell walls	24.4±3.0 a	25.3±5.9 a	5.0±1.2