Plants with reduced asparagine content

A method of preparing plant material with reduced levels of asparagine and reduced levels of acrylamide in aerosol derived from said plant material as compared to plant material from a control plant, said method comprising the steps of:

• (a) providing a plant or part thereof comprising a polynucleotide comprising a sequence encoding an asparagine synthetase and having at least 90% sequence identity to SEQ ID NO:1 or at least 72% sequence identity to SEQ ID NO:3 or SEQ ID NO:5 or SEQ ID NO:7;
• (b) reducing the expression of the polynucleotide or the activity of the protein encoded thereby in the plant or part thereof;
• (c) harvesting plant material from the plant or part thereof;
• (d) drying or curing the plant material;
• (e) optionally, measuring the levels of asparagine in the plant or part thereof and/or measuring the levels of acrylamide in aerosol derived from the plant or part thereof;
• and
• (f) obtaining cured or dried plant material with reduced levels of asparagine and reduced levels of acrylamide in aerosol derived from said plant material, suitably, wherein the level of nicotine is substantially the same as the level of nicotine in the control plant;
• suitably, wherein the formation of glutamine, aspartic acid and glutamic acid is increased as compared to cured or dried leaf of the control plant.

A mutant, non-naturally occurring, or transgenic plant, or part thereof having asparagine synthetase comprising:

• (i) a polynucleotide sequence comprising a sequence having at least 90% sequence identity to SEQ ID NO:1 or at least 72% sequence identity to SEQ ID NO:3 or SEQ ID NO:5 or SEQ ID NO:7;
• or
• (ii) a polypeptide encoded by the polynucleotide set forth in (i);
• or
• (iii) a polypeptide having at least 78% sequence identity to SEQ ID NO:2 or SEQ ID NO:4 or SEQ ID NO:6 or SEQ ID NO:8.