Boron excess imbalances root/shoot allometry, photosynthetic and chlorophyll fluorescence parameters and sugar metabolism in apple plants

Boron (B) excess frequently impair plant performances and their productivity; in particular in arid and semi‐arid environments. In the present experiment; hydroponically‐grown ‘Granny Smith’ apple plants grafted on M9 rootstock were treated with optimal (25 μΜ) or excess (400 μΜ) B for 116 days to evaluate allometric responses of plants to B toxicity and to highlight physiological (photosynthesis and chlorophyll fluorescence) and biochemical (pigment content and sugar metabolism) responses of apple plants to B excess. Boron accumulated principally in top > middle > basal stems and leaves of high‐B‐stressed plants. Notably, the stem dramatically accumulated a higher level of B, as an attempt to preserve leaves, especially the youngest from further B accumulation. B accumulation seriously affected photosynthesis of younger leaves and caused both stomata (reduced stomatal conductance) and biochemical (reduction of apparent CO2 use efficiency and pigment content) limitations and altered the photochemistry and energy partitioning in photosystem II. Boron excess altered leaf sugar proportion; increasing the accumulation of non‐translocating sugars such as glucose and fructose. Our dataset adds knowledge on the effect of B excess in apple tree and poses serious concerns about the possible effect of B in altering sugar metabolism; which, in turn, can strongly affect fruit production of this worldwide‐cropped species

Boron toxicity in higher plants: an update

Main conclusion: In this review, emphasis is given to the most recent updates about morpho-anatomical, physiological, biochemical and molecular responses adopted by plants to cope with B excess. Abstract: Boron (B) is a unique micronutrient for plants given that the range of B concentration from its essentiality to toxicity is extremely narrow, and also because it occurs as an uncharged molecule (boric acid) which can pass lipid bilayers without any degree of controls, as occurs for other ionic nutrients. Boron frequently exceeds the plant’s requirement in arid and semiarid environments due to poor drainage, and in agricultural soils close to coastal areas due to the intrusion of B-rich seawater in fresh aquifer or because of dispersion of seawater aerosol. Global releases of elemental B through weathering, volcanic and geothermal processes are also relevant in enriching B concentration in some areas. Considerable progress has been made in understanding how plants react to B toxicity and relevant efforts have been made to investigate: (I) B uptake and in planta partitioning, (II) physiological, biochemical, and molecular changes induced by B excess, with particular emphasis to the effects on the photosynthetic process, the B-triggered oxidative stress and responses of the antioxidant apparatus to B toxicity, and finally (III) mechanisms of B tolerance. Recent findings addressing the effects of B toxicity are reviewed here, intending to clarify the effect of B excess and to propose new perspectives aimed at driving future researches on the topic

Biotechnology Towards Energy Crops

New crops are gradually establishing along with cultivation systems to reduce reliance on depleting fossil fuel reserves and sustain better adaptation to climate change. These biological assets could be efficiently exploited as bioenergy feedstocks. Bioenergy crops are versatile renewable sources with the potential to alternatively contribute on a daily basis towards the coverage of modern society’s energy demands. Biotechnology may facilitate the breeding of elite energy crop genotypes, better suited for bio-processing and subsequent use that will improve efficiency, further reduce costs, and enhance the environmental benefits of biofuels. Innovative molecular techniques may improve a broad range of important features including biomass yield, product quality and resistance to biotic factors like pests or microbial diseases or environmental cues such as drought, salinity, freezing injury or heat shock. The current review intends to assess the capacity of biotechnological applications to develop a beneficial bioenergy pipeline extending from feedstock development to sustainable biofuel production and provide examples of the current state of the art on future energy crops. © 2016, Springer Science+Business Media New York

Non-food crops to industry schemes for an European Bio-based industry and sustainable agriculture.

general description of the project outline