Alternative Splicing in Plants

Alternative splicing is a mechanism by which a single gene can give rise to more than one distinct mature mRNA, and consequently more than one distinct protein product, called isoforms, simply by varying how its introns (and, in some cases, even some of its exons) are removed and joined during processing. When a gene contains multiple introns, they can be spliced out either separately or together as one unit, and in some genes one or more exons sitting between introns can themselves be skipped and removed along with the surrounding introns, so that the exon content of the final mRNA differs from one splicing event to the next. This has several important consequences: the different protein isoforms produced from a single gene can differ in their amino acid sequence and consequently in their biological function, greatly expanding overall protein diversity without requiring extra genes; one gene can effectively give rise to multiple related mRNA transcripts and hence multiple related proteins, increasing the total number of distinct gene products the genome can generate; and, particularly relevant to plants, alternative splicing plays an important role in how a plant respond …