Effects Of UV Irradiation On Growth And Antioxidants Accumulation In Canola(Brassica Napus L)

Antioxidant compounds are effective in reducing the risk of several chronic illnesses,such as cardiovascular and other degenerative diseases,which are associated with the ability of scavenging free radical.Plants exposed to stressful environment has been recognized a feasible way to increasing antioxidant capacity.Plant factory with artificial lighting can easily realize the control of environmental factors(eg.light,temperature),and obtain the highest antioxidant capacity in plants.Brassica napus L.acts as a model plant and is available for microarray.In this study,UV irradiation was selected as an environmental stressor,which is easily realized in a plant factory.The objective of this study was to optimize the control strategy of UV irradiation for antioxidant compounds production in canola(B.napus L.)plants grown in the plant factory.Effects of different UV irradiation periods and intensities on growth and antioxidant compounds accumulation were investigated.The results indicated that:1)UV irradiation significantly increased antioxidant capacity(ORAC)and antioxidant compound content.However,shoot day weight reduced with increasing UV irradiation intensity;2)12 h·d-1 UV irradiation during light period was found to be more effective in increasing ORAC and antioxidant compound content than UV irradiation during dark period;3)Increasing UV irradiation during light period significantly accelerated the key genes expression of phenylpropanoid biosynthesis pathway and flavonoid biosynthesis pathway,together with ORAC and antioxidant compound content.12 h·d-1 UV irradiation at the intensity of 7.5 W·m-2 was recommended as light parameters for antioxidant compounds production in canola plants grown in the plant factory.