Abstract:

Adenosine diphosphate glucose pyrophosphorylase (AGPase) is the rate-limiting enzyme in the starch synthesis pathway of plants. Cloning the homologous gene of AGPase in Lilium lancifolium and analyzing its expression characteristics are helpful to understand the law of starch synthesis during the growth and development of bulbils, and provide a basis for the development and utilization of bulbils as a seed resource or dietary ingredient. In this study, a gene encoding a small subunit of adenosine diphosphate glucose pyrophosphorylase (LlAGPS1) was cloned from Lilium lancifolium by homologous cloning technology. The expression of LlAGPS1 in leaves and bulbils was analyzed by fluorescence quantitative PCR. The results showed that the protein encoded by LlAGPS1 gene had PLN02241, GlgC conserved domain and belonged to cl33437 super family protein. Protein multiple sequence alignment showed that it had high homology with AGPase small subunit sequences of other crops. The qPCR analysis showed that LlAGPS1 gene was mainly expressed in bulbils, which was significantly higher than that in leaves. The flower bud removal treatment could up-regulate the expression of LlAGPS1 in leaves, and the diurnal variation of the gene expression in leaves and bulbils showed a decreasing trend. The protein encoded by LlAGPS1 gene has PLN02241 and GlgC conserved domains unique to cl33437 family. It is a homologous gene encoding AGPase protein with obvious tissue expression specificity and high expression in the growth and development of bulbils. The results provide a reference for the follow-up study of the effect of LlAGPS1 gene expression regulation technology on the starch synthesis, growth and development of Lilium lancifolium bulbils, and the development of bulbil value.

Key words: Lilium lancifolium, bulbil, adenosine diphosphate glucose pyrophosphorylase, LlAGPS1, gene expression