Histological and Transcriptomic Analysis during Bulbil Formation in Lilium lancifolium

Abstract

Aerial bulbils are an important propagative organ, playing an important role in population expansion. However, the detailed gene regulatory patterns and molecular mechanism underlying bulbil formation remain unclear. Triploid Lilium lancifolium, which develops many aerial bulbils on the leaf axils of middle-upper stem, is a useful species for investigating bulbil formation. To investigate the mechanism of bulbil formation in triploid L. lancifolium, we performed histological and transcriptomic analyses using samples of leaf axils located in the upper and lower stem of triploid L. lancifolium during bulbil formation. Histological results indicated that the bulbils of triploid L. lancifolium are derived from axillary meristems that initiate de novo from cells on the adaxial side of the petiole base. Transcriptomic analysis generated ~650 million high-quality reads and 11,871 differentially expressed genes (DEGs). Functional analysis showed that the DEGs were significantly enriched in starch and sucrose metabolism and plant hormone signal transduction. Starch synthesis and accumulation likely promoted the initiation of upper bulbils in triploid L. lancifolium. Hormone-associated pathways exhibited distinct patterns of change in each sample. Auxin likely promoted the initiation of bulbils and then inhibited further bulbil formation. High biosynthesis and low degradation of cytokinin might have led to bulbil formation in the upper leaf axil. The present study achieved a global transcriptomic analysis focused on gene expression changes and pathways' enrichment during upper bulbil formation in triploid L. lancifolium, laying a solid foundation for future molecular studies on bulbil formation.

Changes in carbohydrate metabolism and endogenous hormone regulation during bulblet initiation and development in Lycoris radiata

“…7). GH3 genes (and especially, GH3.1 (Uni_24954)), encoding IAA-amido synthetase, which conjugates IAA to amino acids, thus reducing the IAA concentration [25], was downregulated throughout bulblet formation.…”

Morphological, structural, and physicochemical properties of starch isolated from different lily cultivars grown in China

“…Histological and transcriptomic analysis showed that starch synthesis and accumulation was vital to bulblet emergence and development in triploid Lilium lancifolium. [12,13] Zhang et al [14] reported that the starch content of interior scales were higher than that of exterior scales. Starches from different tissue parts differed in colors, sizes, structure, morphology, and texture characteristics, which could affect the functional properties and their suitability for different industrial applications.…”

Comparison of Structural and Functional Properties of Starches from the Rhizome and Bulbil of Chinese Yam (Dioscorea opposita Thunb.)

“…Its structural and functional properties have been studied by some previous reports [ 15 , 16 , 17 , 18 ]. The bulbil, also known as Shanyaodou (in Chinese), is an aerial tuber of Chinese yam, which is generated from leaf axil [ 2 , 19 ]. The bulbil can be released from the parent plant and grow independently into a new plant, making it an important propagation organ [ 13 , 19 ].…”

“…The bulbil, also known as Shanyaodou (in Chinese), is an aerial tuber of Chinese yam, which is generated from leaf axil [ 2 , 19 ]. The bulbil can be released from the parent plant and grow independently into a new plant, making it an important propagation organ [ 13 , 19 ]. The bulbil of Chinese yam has been used as an important food in people’s everyday life and as an important ingredient in livestock feed.…”