We often see the availability of food as something that is always there with supermarket shelves always being fully stocked up and access to any type of craving at any given hour. However, there are background struggles in providing access to food to everyone around the world as there are people in less economically developed countries that do not have easy access to the nutrients they need. As the population of the world increases, there are increasing struggles in finding ways to feed everyone with enough food without compromising the quality.
In order to feed the growing population, there needs to be an understanding of new and advanced agricultural techniques but there is an ongoing challenge to possess the funds required. (Alene et al., 2018)
Some techniques that have been adopted include the use of genetically modified organisms ( GMOs) with the purpose of overcoming a specific issue that affects the nutrition or quality of food. Investing time in creating ways to ensure food is of the correct standard is one way to be confident in food security.
Obesity affects around 40% of Oceanias population while Africa and The Caribbean have around 20% of people that do not consume enough calories as recorded by the World Health Organisation. Location, gender and affordability are some factors that determine whether food is available to certain individuals. Cereals are seen to provide most of the energy in many parts of the world. 50% of the daily energy supply were from cereals in 2013. It is inevitable that as the population increases, so will the amount of waste, which has increase by 74% compared to 30 years ago. (Gould, 2017)
The Green Revolution
This was a set of initiatives to give rise to agricultural mechanisms during 1950-60s in order to increase production of food and help feed an increased number of people. This involved using different things such as high-yielding varieties (HYV) (which have a relatively higher nitrogen-absorbing potential) of cereals and chemical fertilisers. Semi-dwarfing genes were implemented into the genomes of these HYV as they would fall over before harvesting. This revolution advanced on already existing technologies. These technologies aimed to improve growth conditions by implementing ideas such as irrigation projects, pesticides and fertilisers. The intention was to improve crop varieties by utilising whatever scientific methods were known at the time.
The Green Revolution has been used to incorporate traditional ways of agriculture to perform jobs such as producing plants with shorter stalks that can concentrate their energy on making more seeds. Fertilisation and irrigation were implemented and there were also ways to control pests. Results of this increased effort were seen when the production of various products such as maize, wheat and rice doubled to 2 million tonnes in 2000 which helped to handle the issue regarding food security.
In order to control the level of food for the population increase by 2050, agricultural production needs to increase by 50% globally. One way to manage this problem would be to decrease the amount of wastage and make better food choices. Moreover, by improving crop yields sustainably and modifying the photosynthesis process, we can also maintain the amount of food. (Bourzac, 2017)
Malthusian principle of population
This presents the idea that the population is growing exponentially while food production is increasing on a linear scale hence the Malthusian catastrophe whereby there is not enough food for the population. Malthus had made predictors relating to famine such as India would fail to feed the growing population but this failed to come into reality as they had used their self sustaining cereal products in 1974 due to Normans dwarf wheat varieties.
Dr. Norman Borlaug Father of the green revolution
Dr. Norman who was an American agronomist won the Nobel Peace Price (1970) amongst other awards for his involvement in improving agricultural production preventing more than a billion lives being lost due to starvation. He carried out experiments that involved the breeding of cultivars that exhibited resistance to rust and had strong stems. These allowed them to stay upright during strong winds. While in Mexico as a researcher, he created wheat varieties that were resistant to disease while also incorporating high yields. These methods were then brought to other places such as Pakistan and India where the wheat production significantly increased in the middle of the 20th Century which had a positive impact on the food security.
The improvement in wheat varieties helped eradicate famine in India and other Asian countries.
(Choudhary et al., 2014)
Photosynthesis occurs in plants and other organisms where chemical energy is produced from light energy.
6CO2 + 6H2O C6H12O6 + 6O2
The equation for photosynthesis is represented above.
This process can be manipulated to enhance the yields of crops and help combat the problem of an increasing population as Krishna Niyogi, a plant biologist has attempted. He has been using plants to understand photosynthesis and trying to conceptualise how plants adapt to changes in light levels by introducing mutations. So far, they have shown that yields in tobacco plants can be improved by altering photosynthesis. There is now research to apply these techniques to food crops. Some ways to use photosynthesis to our advantage is to make plants utilise sunlight more systematically or to help in the usage of carbon dioxide helping to revitalise the metabolism of plants. (Bourzac, 2017)
C4 carbon fixation occurs as a photosynthetic process within various plants. Carbon is required to be utilised in molecules such as sugar so it is extracted for carbon dioxide carbon fixation is the first part of this process. It is referred to as C4 as the first product has four carbon molecules.
C4 plants have a different leaf anatomy to C3 plants, they contain chloroplasts in the mesophyll cells as well as the bundle sheath cells. This helps in transferring carbon dioxide to the RuBisCo enzyme.
Pyruvate is converted to phosphoenolpyruvate (PEP) with the help of the pyruvate orthophosphate dikinase. ATP and inorganic phosphate are also needed. It also produces AMP and inorganic pyrophosphate. After this, carbon dioxide is fixed into oxaloacetate by PEP carboxylase. The reactions are carried out in the mesophyll cells. Malate may be produced at this point, which moves to the bundle-sheath cells. Decarboxylation occurs which produces carbon dioxide and pyruvate. Carbon dioxide is used in the Calvin cycle and pyruvate goes back to the mesophyll cells.
One way in which C4 plants differ from C3 plants is that they contain Kranz anatomy which means their leaves are structurally different. They have two rings of cells surrounding their vascular bundles. Bundle sheath cells are located on the inner side and have chloroplasts which are rich in starch. Mesophyll cells are located as the outer ring. This type of cell formation allows RuBisCo to have concentrated carbon dioxide around it so photorespiration can be avoided.
Benefits of C4
This specialised pathway allows plants to have an advantage in conditions such as high temperatures, drought or situations that involve less nitrogen/carbon dioxide levels. C4 plants lose less water when grown in the same conditions which shows that they have a higher rate of water efficiency allowing more moisture to be retained within the soil. This helps them grow for a longer time.
C4 plants originated about 35 million years ago and is involved in the evolution of 19 different plant families.
Some examples of genetic modifications include Golden Rice and Flavr Savr.
In less economically developed places such as Africa, there are many cases of people becoming blind due to vitamin A deficiency as rice is consumed as a major part of their diet but it lacks in carotenoids. Therefore, Golden rice was introduced as a way to counteract this issue by adding genes to the rice to increase their production of beta-carotene which would increase vitamin A levels after consumption. The genes that were added were obtained from a daffodil (Narcissus pseudonarcissus) and a fungus (Erwinia uredovora) (Bor?m, A., Santos, F. and Bowen, D., 2003)
This was the first crop to be genetically modified in 1994. Two novel genes were introduced into the tomatoes to allow them to retain their firmness which increased their shelf life. A reverse copy of the poligalactonurase gene (antisense) which allows less copies of the poligalactonurase enzyme to be formed. Tomatoes remain firm and do not ripen as fast.
Pectin is a polysaccharide found in the cell wall and is broken down by pectinase and pectinsterase. However, they are not in use anymore due to lack in flavour and high cost.
The genetically modified (GM) tomatoes retained their red colour (their lycopene pigment) but the enzyme activity was reduced by 70-90%. Antisense technology was used to produce this genetically engineered fruit.(Gresshoff, P. (2017) The second gene to be added is related to resistance to kanamycin (an antibiotic) (Raymond E. Sheehy, W., 2018).
To conclude, there is an ongoing battle to ensure that we can provide the necessary nourishment to people globally. By looking at plant processes such as photosynthesis, and how this differs in C4 plants, we can use this to our advantage. Other ways to solve the problem of malnourishment, and their effects have been discussed such as Golden Rice and Flavr Savr.