Individual and interactive effects of temperature, carbon dioxide and abscisic acid on mung bean (Vigna radiata) plants

We studied the effects of temperature, carbon dioxide and abscisic acid on mung bean (Vigna radiata). Plants were grown under 26/22°C or 32/28°C (16 h light/8 h dark) at 400 or 700 μmol mol⁻¹ CO₂ and received ABA application of 0 or 100 μl (10 μg) every other day for three weeks, after eight days of initial growth, in growth chambers. We measured 24 parameters. As individual factors, in 16 cases temperature; in 8 cases CO₂; in 9 cases ABA; and as interactive factors, in 4 cases, each of temperature × CO₂, and CO₂ × ABA; and in 2 cases, temperature × ABA were significant. Higher temperatures increased growth, aboveground biomass, growth indices, photochemical quenching (qP) and nitrogen balance index (NBI). Elevated CO₂ increased growth and aboveground biomass. ABA decreased growth, belowground biomass, qP and flavonoids; increased shoot/root mass ratio, chlorophyll and NBI; and had little role in regulating temperature–CO₂ effects.