as phosphorus, nitrogen, and potassium) from soil, decreasing its fertility. Furthermore, the wood used to cure tobacco in some places leads to deforestation. While some big tobacco producers such as China and the United States have access to petroleum, coal, and natural gas, which can be used as alternatives to wood, most developing countries still rely on wood in the curing process. Brazil alone uses the wood of 60 million trees per year for curing, packaging, and rolling cigarettes. In 2017 WHO released a study on the environmental effects of tobacco. Research Several tobacco plants have been used as model organisms in genetics. Tobacco BY-2 cells, derived from N. tabacum cultivar 'Bright Yellow-2', are among the most important research tools in plant cytology. Tobacco has played a pioneering role in callus culture research and the elucidation of the mechanism by which kinetin works, laying the groundwork for modern agricultural biotechnology. The first genetically modified plant was produced in 1982, using Agrobacterium tumefaciens to create an antibiotic-resistant tobacco plant. This research laid the groundwork for all genetically modified crops. Genetic modification Because of its importance as a research tool, transgenic tobacco was the first genetically modified (GM) crop to be tested in field trials, in the United States and France in 1986; China became the first country in the world to approve commercial planting of a GM crop in 1993, which was tobacco. Field trials Many varieties of transgenic tobacco have been intensively tested in field trials. Agronomic traits such as resistance to pathogens (viruses, particularly to the tobacco mosaic virus (TMV); fungi; bacteria and nematodes); weed management via herbicide tolerance; resistance against insect pests; resistance to drought and cold; and production of useful products such as pharmaceuticals; and use of GM plants for bioremediation, have all been tested in over 400 field trials using tobacco. Production Currently, only the US is producing GM tobacco. The Chinese virus-resistant tobacco was withdrawn from the market in China in 1997. From 2002 to 2010, cigarettes made with GM tobacco with reduced nicotine content were available in the US under the market name Quest. Consumption Tobacco is consumed in many forms and through a number of different methods. Some examples are: Beedi (also known as bidis or biris) are thin, often flavoured cigarettes from India made of tobacco wrapped in a tendu leaf, and secured with coloured thread at one end. Chewing tobacco is