Boron stimulates fruit formation and reprograms the development metabolism

05 Oct 2023
2251

Boron is one of the nutrients required for plant and fruit growth, development, yield and quality. In fact, this element is mainly involved in the structural integrity of cell walls and the functioning of cell membranes in plants.

Boron concentrations are higher in floral tissues than in the vegetative ones, indicating a role for boron in the reproductive process. Boron is not particularly mobile in plant tissues so that it is not easily translocated to the buds, where it is necessary for pollen production, pollen tube growth and other reproductive functions.

Consequently, in a study conducted by researchers from research institutes in Greece and Germany, the effect of pre-bloom boron application on early fruit set and early fruit growth was analyzed. As no information on the molecular level behaviour involved in this process was yet available in the literature, the researchers carried out a transcriptome and metabolome analysis, using the sweet cherry as an experimental model.

The orchard under consideration had 11-year-old plants cv 'Skeena', planted at a spacing of 5 m x 4 m, grafted onto rootstock 'MaxMa 14'. At the green tip stage of the bud, i.e. nine days before flowering, sprays of 0.2% boric acid (32 mM) and 0.02% Tween 20 dissolved in distilled water were applied.

Subsequently, analyses were performed at five separate times at 12, 23, 37, 46 and 63 days after full flowering. The results revealed that the boron content increased in the early stages of growth (between 12 and 23 days after flowering), then decreased to values like those of the untreated fruit, probably due to phloem translocation to other tissues such as leaves and shoots.

Indeed, although in most plant species boron has a low mobility in the phloem, in Prunus species it forms complexes with sorbitol and fructose, which allow it to move through the phloem, thus making it a highly mobile element.

Increased fruit set rate and enlargement of the average mesocarp cell size were the visible results of boron treatment. This may be due to the activation of growth-regulatory genes and a general activation of primary metabolism, which can promote fruit growth.

During the various developmental stages evaluated, carbohydrates (e.g. fructose and glucose), alcohols (e.g. myo-inositol and maltitol), organic acids (e.g. malic acid and citric acid) and amino acids (e.g. valine and serine) accumulated in response to boron application.

Analysis of gene expression in the early stages of growth showed that the genes most responsive to boron treatment were associated with both secondary and amino acid metabolism, ribosome biogenesis, sugar homeostasis and photosynthesis. Boron induced or repressed numerous genes, including those specifically involved in growth.

During the initial growth phase, fruits exposed to boron showed a lower presence of heat shock proteins, which, however, increased during the second growth phase. This study thus represents a first clue to the metabolic pathways activated and repressed by boron application in the early stages of cherry fruit development.

Source: Michailidis, M., Bazakos, C., Kollaros, M., Adamakis, I.-D.S., Ganopoulos, I., Molassiotis, A. et al. (2023), Boron stimulates fruit formation and reprograms developmental metabolism in sweet cherry. Physiologia Plantarum, 175(3), e13946. https://doi.org/10.1111/ppl.13946.

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

Reducing pollution thanks to sour cherry leaves

Health

19 Jan 2024

Adsorption capacities of 524.1 (mg g-1) were obtained for crystal violet and 168.6 (mg g-1) for methylene blue. These capacities significantly exceed those of other comparable adsorbents. The only disadvantage? The inability to regenerate the adsorbent.

ANA Chile® shows promising early cherry varieties in the northern area

Events Varieties

21 Nov 2023

The first part of the event took place at the Hotel Limarí, where consultant Walter Masman and Lorena Pinto, pome and cherry product manager of ANA Chile, presented. On the second day, the Field Day took place in a test block located in Recoleta, Ovalle.

In evidenza

Native cherry trees better support local moths in Massachusetts landscapes

Crop protection

01 Jul 2025

A scientific study confirms native moths thrive best on cherry trees native to Massachusetts. Non-native species slow growth and raise mortality in larvae. Native trees are crucial for preserving biodiversity and supporting birds and insects in gardens and cities.

How genetics shapes cherry flavor: from sweet sorbitol to tart malic acid

Breeding

01 Jul 2025

Researchers from Clemson University and Spain’s CITA discovered the genetic basis of sweetness and acidity in sweet cherries. With QTL mapping and haplotype analysis, breeders can now develop better-tasting, more stable varieties tailored to consumer preferences in Europe.

Tag Popolari