Coetzer C, Corsini D, Love S, Pavek J, Tumer N
Biotechnology Center for Agriculture and the Environment and Department of Plant Pathology, Rutgers University, Cook College, P.O. Box 231, New Brunswick, New Jersey 08903-0231, USA.
J Agric Food Chem. 2001 Feb;49(2):652-7. doi: 10.1021/jf001217f.
Polyphenol oxidase (PPO) activity of Russet Burbank potato was inhibited by sense and antisense PPO RNAs expressed from a tomato PPO cDNA under the control of the 35S promoter from the cauliflower mosaic virus. Transgenic Russet Burbank potato plants from 37 different lines were grown in the field. PPO activity and the level of enzymatic browning were measured in the tubers harvested from the field. Of the tubers from 28 transgenic lines that were sampled, tubers from 5 lines exhibited reduced browning. The level of PPO activity correlated with the reduction in enzymatic browning in these lines. These results indicate that expression of tomato PPO RNA in sense or antisense orientation inhibits PPO activity and enzymatic browning in the major commercial potato cultivar. Expression of tomato PPO RNA in sense orientation led to the greatest decrease in PPO activity and enzymatic browning, possibly due to cosuppression. These results suggest that expression of closely related heterologous genes can be used to prevent enzymatic browning in a wide variety of food crops without the application of various food additives.
在花椰菜花叶病毒35S启动子的控制下，由番茄多酚氧化酶（PPO）cDNA表达的正义和反义PPO RNA抑制了褐皮伯班克马铃薯的多酚氧化酶（PPO）活性。来自37个不同品系的转基因褐皮伯班克马铃薯植株在田间种植。对从田间收获的块茎进行PPO活性和酶促褐变水平的测定。在抽样的28个转基因品系的块茎中，有5个品系的块茎褐变减少。这些品系中PPO活性水平与酶促褐变的降低相关。这些结果表明，正义或反义方向的番茄PPO RNA表达抑制了主要商业马铃薯品种中的PPO活性和酶促褐变。正义方向的番茄PPO RNA表达导致PPO活性和酶促褐变的最大程度降低，这可能是由于共抑制作用。这些结果表明，密切相关的异源基因的表达可用于在不使用各种食品添加剂的情况下防止多种粮食作物中的酶促褐变。
