VITAMIN A DEFICIENCY (VAD) NOT ONLY LEADS TO BLINDNESS BUT ALSO INCREASES THE RISK OF DISEASE AND MORTALITY FROM SEVERE INFECTIONS DUE TO WEAKENED IMMUNE RESPONSES. INSUFFICIENT DIETARY INTAKE IS THE LEADING CAUSE OF VAD, WHICH CAN BE ALLEVIATED BY BIOFORTIFYING STAPLE CROPS WITH INCREASED PROVITAMIN A CAROTENOIDS--PRECURSORS FOR VITAMIN A BIOSYNTHESIS IN HUMANS. WHEAT IS A MAJOR DIETARY STAPLE, BUT ITS GRAINS ARE LOW IN PROVITAMIN A CAROTENOIDS. THIS RESEARCH AIMS TO UNDERSTAND THE FUNCTION OF FOUR CAROTENOID CLEAVAGE DIOXYGENASES (CCDS) AND HOW THEY MAY AFFECT THE BREAKDOWN OF PROVITAMIN A CAROTENOIDS IN WHEAT GRAINS. THE KNOWLEDGE GAINED AND THE CCD MUTANT LINES DEVELOPED FROM THIS RESEARCH WILL SERVE AS VALUABLE RESOURCES TO BLOCK THE TURNOVER OF PROVITAMIN A CAROTENOIDS AND ENHANCE THE NUTRITIONAL QUALITY OF WHEAT GRAINS.