Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada.
J Sci Food Agric. 2019 Dec;99(15):6850-6858. doi: 10.1002/jsfa.9970. Epub 2019 Sep 10.
Transparent Testa8 (TT8) and Homeobox12 (HB12) are two transcriptional factors in plant phenylpropanoid pathways and were reported to be positively related to lignin content. Alfalfa with silenced TT8 (TT8i) and HB12 (HB12i) was therefore generated using the RNA interference (RNAi) technique. Although lignin was found to be high in HB12i, such gene-silencing of alfalfa resulted in nutrient profiles that might be suitable for grazing. To extend the nutritional evaluation of transformed alfalfa, ground samples of 11 HB12i, 5 TT8i and 4 wild type (WT) were incubated in rumen fluid : buffer solution for 0, 2, 4, 8, 12, 24 and 48 h at 39 °C. Dry matter (DM) and neutral detergent fiber (NDF) degradations at each time point, and production of volatile fatty acids (VFA) at 4, 12, 24 and 48 h were analyzed, as well as degradation and production kinetics. The correlations and regressions between nutritive profiles and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectral parameters were determined.
Both transformed genotypes had lower DM degradation and HB12i had lower VFA production compared with WT. Structural carbohydrate (STC) parameters were found to be negatively correlated with DM degradation and VFA production. The kinetics of DM degradation and VFA production were predicted from spectral parameters with good estimation power.
Silencing of HB12 and TT8 affected fermentation characteristics of alfalfa and some fermentation characteristics were predictable from spectral parameters using ATR-FTIR spectroscopy. © 2019 Society of Chemical Industry.
透明种皮 8（TT8）和同源盒 12（HB12）是植物苯丙素途径中的两个转录因子，据报道与木质素含量呈正相关。因此，利用 RNA 干扰（RNAi）技术生成沉默 TT8（TT8i）和 HB12（HB12i）的紫花苜蓿。虽然 HB12i 中的木质素含量较高，但苜蓿的这种基因沉默导致其营养成分可能适合放牧。为了扩展转化苜蓿的营养评价，将 11 个 HB12i、5 个 TT8i 和 4 个野生型（WT）的苜蓿-ground 样本在 39°C 的瘤胃液：缓冲液中孵育 0、2、4、8、12、24 和 48 h。分析每个时间点的干物质（DM）和中性洗涤剂纤维（NDF）降解以及 4、12、24 和 48 h 时挥发性脂肪酸（VFA）的产生情况，以及降解和产生动力学。确定营养谱与衰减全反射傅里叶变换红外（ATR-FTIR）光谱参数之间的相关性和回归关系。
与 WT 相比，两种转化基因型的 DM 降解率较低，HB12i 的 VFA 产量较低。结构碳水化合物（STC）参数与 DM 降解和 VFA 产生呈负相关。使用 ATR-FTIR 光谱学，可以从光谱参数中预测 DM 降解和 VFA 产生的动力学。
沉默 HB12 和 TT8 影响了苜蓿的发酵特性，一些发酵特性可以从光谱参数中预测。
