Effects of Transparent Testa8(TT8) gene and Homeobox12(HB12) gene silencing in alfalfa(Medicago sativa L.) on molecular structure spectral profile in relation to energy,degradation,and fermentation characteristics in ruminant systems  

作　　者：Yaogeng Lei Abdelali Hannoufa Peiqiang Yu 

机构地区：[1]Department of Animal and Poultry Science,College of Agriculture and Bioresources,University of Saskatchewan,51 Campus Drive,Saskatoon,SK S7N5A8,Canada [2]London Research and Development Centre,Agriculture and Agri-Food Canada,1391 Sandford Street,London,ON N5V 4T3,Canada

出　　处：《Animal Nutrition》2023年第3期79-87,共9页动物营养（英文版）

摘　　要：Alfalfa(Medicago sativa L.) is a legume forage that is widely cultivated owing to its high biomass yield and favorable nutrient values. However, alfalfa contains relatively high lignin, which limits its utilization.Downregulation of two transcriptional factors, Transparent Testa8(TT8) and Homeobox12(HB12), has been proposed to reduce lignin content in alfalfa. Therefore, silencing of TT8(TT8i) and HB12(HB12i) in alfalfa was achieved by RNAi technology. The objective of this project was to determine effect of gene modification through silencing of TT8 and HB12 genes in alfalfa plants on lignin and phenolic content,bioenergic value, nutrient supply from rumen degradable and undegradable fractions, and in vitro ammonia production in response to the silencing of TT8 and HB12 genes in alfalfa. All gene silenced alfalfa plants(5 TT8i and 11 HB12i) were grown under greenhouse conditions with wild type as a control.Samples were analyzed for bioactive compounds, degradation fractions, truly digestible nutrients, energetic values and in vitro ammonia productions in ruminant systems. Furthermore, relationships between physiochemical, metabolic and fermentation characteristics and molecular spectral parameters were determined using vibrational molecular spectroscopy. Results showed that the HB12i had higher lignin, while TT8i had higher phenolics. Both silenced genotypes had higher rumen slowly degraded carbohydrate fractions and truly digestible neutral detergent fiber, but lower rumen degradable protein fractions. Moreover, the HB12i had lower truly digestible crude protein, energetic values and ammonia production compared with other silenced genotypes. In addition, in relation to the nutritive values of alfalfa, structural carbohydrate parameters were negatively correlated, whereas alpha/beta ratio in protein structure was positively correlated. Furthermore, good predictions were obtained for degradation of protein and carbohydrate fractions and energy values from molecular spectral parameters. In conclusion, silencing of

关 键 词：Gene silencing Homeobox12(HB12)gene Transparent Testa8(TT8)gene Alfalfa(Medicago sativa L.) Ruminant system Fermentation and degradation 

分 类 号：S54[农业科学—作物学]