Auxin

Enzyme

Wild type

Mutant

Botany

Gene

Dehydrogenase

Cytokinin

Biology

Transgene

Genetically modified crops

Biochemistry

Frontiers in Plant Science

Barley is one of the most important cereals, which is used for breweries, animal and human feeds. Genetic manipulation of plant hormone cytokinin (CK) levels may influence several physiological processes, besides others stress tolerance, root formation and crop yield. In planta, endogenous CK status is finely regulated by the enzyme cytokinin dehydrogenase (EC 1.5.99.12; CKX), that irreversibly cleaves the N6-side chain of adenine-derived CKs. Increasing grain yield by mean of manipulation of endogenous CK content was assayed by the silencing of the HvCKX1 gene. Moreover, to elucidate the putative role of HvCKX1 gene on grain production, knocked-out Hvckx1 mutant plants were generated using RNA-guided Cas9 system. Homozygote transgenic plants with silenced HvCKX1 gene and azygous knock-out Hvckx1 mutants have been selected and analysed. Both reduced expression of HvCKX1 gene and CKX activity were measured in different stages of barley grain development. Phenotyping of the transgenic lines revealed reduced roo...

Modification of Barley Plant Productivity Through Regulation of Cytokinin Content by Reverse-Genetics Approaches