The theoretical limit, defined as the fraction of light energy that is captured in conversion of CO 2 and water to glucose, is ~12% (ref. Photosynthesis is relatively conserved among crops and its efficiency is well below the theoretical maxima 9, 10, 11. Photosynthesis is a promising target to increase yield. Indeed, yield is stagnating in most major crops 5, 6, 7, 8.
Most breeding efforts during the Green Revolution addressed pathogen resistance and brought plant architecture and the harvest index close to their theoretical upper limit 3, 4. Future gains face the challenges of shrinking farmland area, an increasingly unpredictable climate and the environmental imperative to use less fertilizer and agrochemicals, and will require new breeding strategies. This gain was achieved without expanding cropland, by extensive use of fertilizer and plant protection agents as well as improved crop varieties. Modern agriculture has witnessed an ~160% increase in global production since the 1950s. Our analyses identify distinct flux patterns supporting faster growth in photosynthetic cells, with some of the algae exhibiting faster ribulose 1,5-bisphosphate regeneration and increased fluxes through the lower glycolysis and anaplerotic pathways towards the tricarboxylic acid cycle, amino acid synthesis and lipid synthesis than in higher plants.Īn increase in agricultural yield of 70% or more is required by 2050 to meet the growing demand of the world population 1, 2. We estimated flux patterns in these algae and compared them with published and new data from C 3 and C 4 plants. Using a tailor-made microfluidics labelling system to supply 13CO 2 at steady state, we investigated in vivo labelling kinetics in intermediates of the Calvin Benson cycle and sugar, starch, organic acid and amino acid synthesis pathways, and in protein and lipids, in Chlamydomonas reinhardtii, Chlorella sorokiniana and Chlorella ohadii, which is the fastest growing green alga on record. Whilst empirical studies have shown that photosynthetic efficiency is higher in microalgae than in C 3 or C 4 crops, the underlying reasons remain unclear.
Photosynthesis-related pathways are regarded as a promising avenue for crop improvement.
0 kommentar(er)
