Knowledge and technologies for sustainable intensification of food production

Mitochondrial function modulates touch signalling in Arabidopsis thaliana

Plants respond to short- and long-term mechanical stimuli, via altered transcript abundance and growth respectively. Jasmonate, gibberellic acid and calcium have been implicated in mediating responses to mechanical stimuli. Previously it has been shown that the transcript abundance for the outer mitochondrial membrane protein of 66 kDa (OM66), is induced several fold after 30 min in response to touch. Therefore, the effect of mitochondrial function on the response to mechanical stimulation by touch at 30 min was investigated. Twenty-five mutants targeting mitochondrial function or regulators revealed that all affected the touch transcriptome. Double and triple mutants revealed synergistic or antagonistic effects following the observed responses in the single mutants. Changes in the touch-responsive transcriptome were localised, recurring with repeated rounds of stimulus. The gene expression kinetics after repeated touch were complex, displaying five distinct patterns. These transcriptomic responses were altered by some regulators of mitochondrial retrograde signalling, such as cyclic dependent protein kinase E1, a kinase protein in the mediator complex, and KIN10 (SnRK1 - sucrose non-fermenting related protein kinase 1), revealing an overlap between the touch response and mitochondrial stress signalling and alternative mitochondrial metabolic pathways. Regulatory network analyses revealed touch-induced stress responses and suppressed growth and biosynthetic processes. Interaction with the phytohormone signalling pathways indicated that ethylene and gibberellic acid had the greatest effect. Hormone measurements revealed that mutations of genes that encoded mitochondrial proteins altered hormone concentrations. Mitochondrial function modulates touch-induced changes in gene expression directly through altered regulatory networks, and indirectly via altering hormonal levels.

Trade and commerce in improved crops and food: an essay on food security

Agricultural trade between nations is a significant proportion of total international trade. Agricultural trade in transgenic crops faces extra complications due to the existence of domestic and international regimes that focus specifically on agricultural biotechnology. These specialized regimes create legal and commercial challenges for trade in transgenic crops that have significant implications for the food security of the nations of the world. By food security, one should understand not just the available supply of food, but also the quality of the food and the environmental impact of agricultural production systems. These specialized regimes for transgenic crops can either encourage or hinder the adoption of agricultural biotechnology as a sustainable intensive agriculture. Sustainable intensive agriculture offers hope for agronomic improvements for agricultural production, socio-economic betterment for farmers and environmental benefits for societies. Sustainable intensive agriculture offers particular hope for the poorest farmers of the world because agricultural biotechnology is a technology in the seed.