Unlike genetic changes, epigenetic changes do not involve changes in DNA sequences, rather the DNA and the protein surrounding the DNA sequence are modified in a way that affects whether the gene is switched on or off. For example, DNA and the histone proteins can be methylated so that the gene activity is active or inactive.
Plants undergo epigenetic changes that lead to their different looks, for example, making leaves when they are young and flowers when they mature. Plants also use epigenetic mechanisms to adapt to new growing conditions like climate changes or global warming. Plants make these changes in order to survive the stressful conditions. The mechanisms enable the plants to memorize, adapt and become tolerant of heat, drought or immune to diseases. Understanding epigenetic mechanisms will help us face and understand climate change.