ENDOSPERM MODIFIERS MEDIATED EXPRESSION OF PROLAIM- LIKE FRACTION AND ITS ROLE IN VITREOUS KERNEL DEVELOPMENT IN MAIZE

Abstract

Maize kernel texture and protein quality are known to be inversely related to each other. Vitreous kernel texture of maize endosperm is defined by regular starch protein matrix. Zein is the protein fraction which is solely responsible for vitreous kernel National Seminar on ‘’Maize for Crop Diversification under Changing Climatic Scenario’’, Ludhiana, Feb 09-10, 2020 94 texture. Considering protein quality the endosperm protein are broadly classified as nutritionally poor zein (prolamin and prolaminlike) and nutritionally rich nonzein (albumin, globulin, glutelinlike and glutelin). It is well established that protein quality is immensely increased in opaque-2 mutants due to increase in nonzein fractions over zein, whereas in QPM both protein quality and kernel texture is retained due to introgression of opaque-2 gene along with endosperm modifiers. The present study was planned to analyse the translational response of endosperm modifiers in QPM, in comparison to normal and opaque-2 counterparts. The results revealed that among different protein fractions viz: albumin, globulin, prolamin, prolaminlike, glutelinlike and glutelin only prolaminlike fraction was found to be retained maximally in QPM lines (14.91%) in comparison to opaque-2 (11.76%) and normal (11.88%) lines. Along with it 27 KDa gamma zein was found to be the major prolamin like protein involved in retrieving vitreous kernel texture in QPM background. Overall present study benefits with fact that the significant difference in prolaminlike fraction among normal and QPM lines can be used as a quick marker to analyse visually indistinguishable high and low protein quality lines, so estimation of prolaminlike fraction can act supplementary biochemical marker for analysing developing QPM lines