Effect of boron and zinc application on HXK1 and MAKR6 gene expression in strawberry.

Boron (B) and zinc (Zn) are important microelements for normal plant activity; their effect have long been studied in numerous agronomical and molecular researches, whereas the interaction of B-Zn remains poorly understood at genomic and transcriptomic levels. Strawberry (fragaria x ananassa) plants were analyzed after single B (80 g/Hl of boron ethanolamine) or Zn (40 g/Hl of Zn-EDTA), and combined B+Zn (80 g/Hl of boron ethanolamine + 40 g/Hl of Zn-EDTA) foliar applications. Leaves, white and red fruits of two genotypes (Candonga and PZ600F13P2 breeding line) were studied. The microelement effects were observed in two conditions: short-term (1 day after treatment) and long-term (20 days after treatment). The differential transcriptomic profiles were analyzed applying RAPD-PCR method. Two genes, HXK1 and MAKR6 have been recognized in differently expressed sequenced amplicons and their expression level was measured using quantitative Real-Time PCR. Fertilizing had an influence on studied genes, their expression differed in relation to the genotype, time course and kind of treatment. Reaction of HXK1 and MAKR6 varied regarding the singular microelement treatments in front of Control (without any treatment) as well as relatively to the combined fertilizing, even if often the zinc effect was “masked” by boron influence in B+Zn treatment. The present study confirmed an initial hypothesis of a significant effects of B and Z in strawberry fruit development. The obtained results, even if they increase the knowledge about the B and Zn effects, could be considered as a first step to details this physiological mechanisms on strawberry fruit development.