| Used the fruits of Camellia oleifera and Camellia meiocarpa as material,this paper was studied the effects of different moisture on internal physiology of Camellia mature seeds,explored mechanisms of change in oil content of seed by physiological-biochemical indexes,revealed relative expression regularity of the four key enzyme genes in oil metabolism by the real-time quantitative RT-PCR,discussed differences oil metabolism between the two species in diffrenct moisture content.Theses provided theoretic foundation for regulation the oil content and ingredient of Camellia.The main results were as follows:(1)The moisture content in the mature seeds of C.oleifera and C.Meiocarpa began to decrease with the extension of storage time,the seed oil content of these two fruits first increased and then decreased with the decline of seed moisture content.The oil content of seed in C.oleifera and C.meiocarpa reaching the maximum were 47.89%and 42.21%respectively,at the moisture content of 30%.These illustrated that oil ripening of Camellia seeds was at 30%moisture content.(2)The amylum content was declining with the decline of seed moisture content in C.oleifera and C.Meiocarpa,the contents of soluble sugar,reducing sugar,sucrose and soluble protein decreased first and then increased with the decline of seed moisture content,reaching the minimum at 30%moisture content.There was a significant negative correlation between the oil content and the soluble sugar content and reducing sugar content in the two seeds,these indicated that these nutrient contents showed a opposite regularity with the oil metabolism,and certain relationship between oil and sugar metabolism.(3)The saturated fatty acids content decreased with the decline of seed moisture content in seeds of C.oleifera and C.meiocarpa,while the unsaturated fatty acids content increased.In unsaturated fatty acids,the oleic acid content increased,the linoleic acid and ?-linolenic acid contents decreased with the reduction of seed moisture content.The results showed that the saturated fatty acids in seeds may transform into unsaturated fatty acids in the process of oil ripening,and the linoleic acid and ?-linolenic acid in the unsaturated fatty acids may gradually transform into oil acid.(4)The ABA content increased first and then decreased with the decline of seed moisture content in C.oleifera and C.Meiocarpa,which was similar to oil metabolism.There was a certain correlation between ABA and oil synthesis and decomposition.ABA may promote the accumulation of oil.There were a extremely significant and a positive correlation between GA3 content and oil content in the seeds of C.oleifera and C.Meiocarpa.There were a extremely significant and a extremely positive correlation respectively between GA3 content and reducing sugar content in C.oleifera and C.Meiocarpa Respectively.It may indicate that GA3 promote the accumulation of oil,and have different effect in different Camellia species.There was a high significant positive correlation between IAA content and ABA content in C.Oleifera,and which means IAA and ABA have offset effect.(5)The ACCase activity increased at first,and then decreased with the decline of seed moisture content in the seeds of C.oleifera and C.Meiocarpa.The ACCase activity of seeds in C.oleifera and C.meiocarpa reached the maximum value at 161.17 pg·g-1 and 256.13 pg·g-1 respectively,at 30%seed moisture content.The activities of SAD,DGAT,KCS,Kas and caleosin showed a decreasing trend during nature drying in two species seeds.There was a negative correlation between the SAD activity and the oleic acid content,which indicated that SAD constantly played a catalytic role during the ripening of Camellia oil.The real-time quantitative RT-PCR analysis revealed relative expression regularity of the genes such as ACCase,KCS,Kas,caleosin in diffrenct seed moisture content,which agreed with the change in enzyme activity.The results can confirm the metabolic regularity of oil related enzymes. |
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