The brachytic 2 and 3 maize double mutant shows alterations in plant growth and embryo development

In maize there are three types of brachytic mutants (br1, br2 and br3) showing short stature and a gibberellins-insensitive phenotype. So far only the brachytic 2 gene has been cloned and it encodes for a putative protein of the Multidrug Resistant (MDR) class of P-glycoproteins (PGPs) that could be involved in polar movement of auxins: in fact the br2 mutant is insensitive to treatment with auxins and gibberellins. We have isolated a new recessive mutation of br2 gene (named br2-23) and with the aim of study its interactions with the other brachytic mutations we produced a br2 br3 double mutant that showed an additive effect on the stature with respect to the single mutants br2 and br3 and abnormal growth. In the progeny of the selfed double mutant we observed various defective seedlings, mirroring an altered embryo development and growth, which also suggested a role for the br3 gene in auxin transport. Expression analysis of the auxin efflux transporters codified by ZmPIN1 genes supports this finding, showing the up-regulation of the ZmPIN1a gene in the br3 mutant. To our knowledge this is the first report showing the involvement of Br2 and Br3 genes in embryo development. These single and double mutants appear to be useful tools to study the genetics of plant height and to investigate auxin transport in plants.     

Study and characterization of a novel functional food: purple popcorn

Many phytonutrients seem to be able to combat the effects of oxidants which may lead to chronic diseases. Among them, anthocyanins have been studied for a long time, and different types of functional foods rich in these pigments are already available on the market. In particular, wine, berries and various cereals have already aroused consumers’ awareness, and in this context we propose a new and attractive healthy food: purple popcorn. Popcorn is the most popular American snack, now well known all over the world. A corn rich in anthocyanins, suitable to be transformed into a snack, could help to introduce healthy antioxidant compounds into the diet of many people, contributing to the prevention of chronic diseases. In this work we developed a coloured popcorn variety rich in anthocyanins (about 66 mg/100 g, mainly cyanidin) by a recurrent selection scheme, with the aim of obtaining a healthier snack. The selection was based on some quality characteristics such as anthocyanin content, popping ability and the popping expansion volume. The purple popcorn obtained was further analyzed by high pressure liquid chromatography and 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, before and after microwave treatment. The results obtained showed that, even though the microwave treatment reduced the anthocyanin content to about 46 %, the remaining anthocyanins exhibited a marked antioxidant capacity compared to the colourless control. Finally taste perception was also checked between coloured and uncoloured popcorn, and no difference was perceived.