High-lysine maize: the key discoveries that have made it possible

Area of Science:

• Agricultural Science
• Plant Molecular Biology
• Nutritional Biochemistry

Background:

• The study of cereal crop storage proteins was revolutionized by the 1964 discovery of high lysine content in opaque-2 (o2) maize mutants.
• This finding introduced a new paradigm for enhancing the nutritional quality of cereal seeds.

Purpose of the Study:

• To review key scientific contributions in the development of high-lysine plants.
• To highlight advances in maize research as a primary example of progress in this field.
• To briefly acknowledge relevant studies in other species like barley and tobacco.

Main Methods:

• Historical review of seminal research in plant protein quality.
• Focus on genetic and biochemical studies of maize mutants, particularly opaque-2.
• Synthesis of findings from 45 years of research in high-lysine crop development.

Main Results:

• The identification of opaque-2 mutants demonstrated the potential for significantly improving essential amino acid content in maize endosperm.
• Decades of research have led to a comprehensive understanding of the genetic and molecular mechanisms underlying lysine biosynthesis and storage protein regulation in maize.
• Significant progress has been made towards the commercial release of genetically engineered high-lysine maize varieties.

Conclusions:

• The initial discovery of high-lysine maize mutants has had a profound and lasting impact on plant science and agriculture.
• Continued research has culminated in the near-term availability of nutritionally enhanced maize, addressing global food security and quality challenges.
• The principles and techniques developed in maize are applicable to improving other cereal crops and model plants.