All plants have a protection against the surrounding environment called a cuticle coating. When this cuticle coating is constructed it is believed that the family of protein called lipid transfer proteins (LTPs) is involved. The LTPs are small and cysteine rich. In Marchantia polymorpha the groups of LTPs called LTPd and LTPg can be found. 8 and 4 in each group respectively. In the genes of LTPd there is an intron placed downstream of the start codon. Firstly, a sequence database search was performed and LTPd2 and LTPd3 were chosen for further experiments in this study. Secondly, a control that the intron was present in the samples were done by preforming a PCR reaction of cDNA from isolated RNA taken from untreated Marchantia polymorpha. A gel electrophoresis of the product was also performed. Lastly, the amount of alternative splicing in LTPd2 and LTPd3 from Marchantia polymorpha after treated with cold and dehydration were studied using quantitative PCR. For the qPCR MpACT and the exon of respective gene were used as references. The ΔCt values and the expression fold (2ΔΔCt) calculated from the qPCR results showed that most of the transcript with introns preserved were upregulated after subjected to stress. Only the intron in MpLTPd2 and MpLTPd3 with MpACT as reference showed a small downregulation after the cold treatment. The intron in MpLTPd3 with MpLTPd3s exon as reference didn’t show any difference. None of the intron transcript in any of the genes on the other hand showed any significant difference in the alternative splicing. This could be because of small sample groups when the test was performed. In conclusion, there were no significant difference in intron expression between treated and control samples. Therefore, nothing can be said about the change in alternative splicing in MpLTPds after cold and dehydration treatments.

Due to global warming, our planet will experience more extreme weather conditions. Plants can protect themselves against these abiotic stress conditions with their stress response, which includes alternative splicing of certain genes. Alternative splicing is a post-transcriptional process where a single gene gives rise to different mRNAs, which in turn produces different proteins. In plants, this is usually done by intron retention. One type of protein that may be involved in this stress response are the non-specific lipid transfer proteins (LTPs). Indeed, evidence of intron retention has been found in the LTP genes in the liverwort Marchantia polymorpha, called MpLTPd. To investigate whether this alternative splicing is caused by abiotic stress or not, I subjected the moss to two different types of stress trials, drought and cold, and compared the general expression of the intron in MpLTPd2 and MpLTPd3 from the stressed samples to samples from a moss grown under normal conditions. I found that the expression of the intron did change in the stressed moss, but none of the differences were significant. This suggests that alterative splicing in MpLTPd2 and MpLTPd3 is not caused by cold and drought and that the intron-containing protein plays no role in the protection of M. polymorpha against abiotic stress.