The Use of Gene Modification and Advanced Molecular Structure Analyses towards Improving Alfalfa Forage.
Alfalfa is one of the most important legume forage crops in the world. In spite of its agronomic and nutritive advantages, alfalfa has some limitations in the usage of pasture forage and hay supplement. High rapid degradation of protein in alfalfa poses a risk of rumen bloat to ruminants which could cause huge economic losses for farmers. Coupled with the relatively high lignin content, which impedes the degradation of carbohydrate in rumen, alfalfa has unbalanced and asynchronous degradation ratio of nitrogen to carbohydrate (N/CHO) in rumen. Genetic engineering approaches have been used to manipulate the expression of genes involved in important metabolic pathways for the purpose of improving the nutritive value, forage yield, and the ability to resist abiotic stress. Such gene modification could bring molecular structural changes in alfalfa that are detectable by advanced structural analytical techniques. These structural analyses have been employed in assessing alfalfa forage characteristics, allowing for rapid, convenient and cost-effective analysis of alfalfa forage quality. In this article, we review two major obstacles facing alfalfa utilization, namely poor protein utilization and relatively high lignin content, and highlight genetic studies that were performed to overcome these drawbacks, as well as to introduce other improvements to alfalfa quality. We also review the use of advanced molecular structural analysis in the assessment of alfalfa forage for its potential usage in quality selection in alfalfa breeding.
Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada. yal263@mail.usask.ca.
Yaogeng
Y
Lei
Agriculture and Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3, Canada. abdelali.hannoufa@agr.gc.ca.
Abdelali
A
Hannoufa
Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada. peiqiang.yu@usask.ca.
Peiqiang
P
Yu
D000220:Adaptation, Biological; D000821:Animal Feed; D000818:Animals; D000872:Anthocyanins / Q000096:biosynthesis; D018533:Biomass; D005818:Genetic Engineering; D060434:Herbivory; D008031:Lignin / Q000096:biosynthesis; D000455:Medicago sativa / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D009753:Nutritive Value; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D030821:Plants, Genetically Modified; D044945:Proanthocyanidins / Q000096:biosynthesis; D012418:Ruminants; D017550:Spectroscopy, Fourier Transform Infrared; D013312:Stress, Physiological
D000872:Anthocyanins; D010940:Plant Proteins; D044945:Proanthocyanidins; C013221:proanthocyanidin; D008031:Lignin
alfalfa; genetic modification; lignin; molecular structure; proanthocyanidin and anthocyanins; transcription factors