Root Temperature and Aeration Effects on the Protein Profile of Canola Leaves

Abstract

Canola (Brassica napus L.) is planted in early spring and must survive both low soil temperatures and periods of wet weather. Shoot effects result from both low root temperature and low aeration, but little is known about the interaction between these two environmental factors, particularly with respect to changes in gene products. In this study, canola plants (‘46A65’) were treated in solution culture. Shoot temperatures were maintained at day/night temperatures of 24/18°C, while roots were maintained at an ambient temperature of 24/18°C, or cooled to 10°C. Roots were either aerated, or not aerated to create hypoxic treatments. Plants with roots in cold and hypoxic solution accumulated starch in the root, and had greater reductions in fresh weight and leaf area than those in either cold or hypoxic treatments alone. Twenty‐one changes in protein expression were also found in the cold hypoxic treatment, 17 of which were not found in either cold or hypoxic treatments alone. Gene products up‐regulated in leaves included cytochrome oxidase Subunit I (COX1) in response to hypoxia, elongation factor eEF1 γ chain in plants with cooled roots, and chaperonin 10 when roots were cooled without aeration. Results demonstrate the interaction between multiple stresses on a molecular level, and suggest that flooding under cool soil temperatures will be more detrimental to canola than that which occurs at warmer temperatures.