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Somatic embryogenesis and organogenesis in Lilium pumilum were successfully regulated by picloram, α-naphthaleneacetic acid (NAA), and 6-benzyladenine (BA). In organogenesis, the highest shoot regeneration frequency (92.5%) was obtained directly from bulb scales on Murashige and Skoog (MS) medium containing 2.0 mg L−1 BA and 0.2 mg L−1 NAA, while organogenic callus (OC) formed from leaves on MS medium supplemented with 1.0 mg L−1 BA and 0.5 mg L−1 NAA. Following subculture, 76.7% of OC regenerated shoots. In somatic embryogenesis, the combination of picloram and NAA increased the amount of embryogenic callus (EC) that formed with a maximum on 90.7% of all explants which formed 11 somatic embryos (SEs) per explant. Differences between EC and OC in cellular morphology and cell differentiation fate were easily observed. SEs initially formed via an exogenous or an endogenous origin. The appearance of a protoderm in heart-shaped SE and the bipolar shoot–root development in oval-shaped SE indicated true somatic embryogenesis. This protocol provides a new and detailed regulation and histological examination of regeneration pattern in L. pumilum.

Rhizosphere CO2 is vital for crop growth, development, and productivity. However, the mechanisms of plants&rsquo, responses to root-zone CO2 are unclear. Oriental melons are sensitive to root-zone gas, often encountering high root-zone CO2 during cultivation. We investigated root growth and nitrogen metabolism in oriental melons under T1 (0.5%) and T2 (1.0%) root-zone CO2 concentrations using physiology and comparative transcriptome analysis. T1 and T2 increased root vigor and the nitrogen content in the short term. With increased treatment time and CO2 concentration, root inhibition increased, characterized by decreased root absorption, incomplete root cell structure, accelerated starch accumulation and hydrolysis, and cell aging. We identified 1280 and 1042 differentially expressed genes from T1 and T2, respectively, compared with 0.037% CO2-grown plants. Among them, 683 co-expressed genes are involved in stress resistance and nitrogen metabolism (enhanced phenylpropanoid biosynthesis, hormone signal transduction, glutathione metabolism, and starch and sucrose metabolism). Nitrogen metabolism gene expression, enzyme activity, and nitrogen content analyses showed that short-term elevated root-zone CO2 mainly regulated plant nitrogen metabolism post-transcriptionally, and directly inhibited it transcriptionally in the long term. These findings provided a basis for further investigation of nitrogen regulation by candidate genes in oriental melons under elevated root-zone CO2.

In order to illuminate the effect of calcium on the IAA signal transduction, we studied the expression of eight SlIAA genes which were up-regulated by calcium during the abscission after short-term (1 h) and long-term (16 h) treatments with calcium, IAA and calcium inhibitors. The results indicated that calcium induced SIIAAs expression in 1 h at low concentration, EGTA affected little SIIAAs expression; it also increased IAA-induced transcript level of SIIAAs, TFP (named trifluoperazine) decreased most SIIAAs expression below the level of calcium combined with IAA-induced expression, except for SlIAA17. Long-term treatment of calcium or calcium inhibitors suppressed some SIIAAs expression, whereas TFP enhanced all SIIAAs expression. Interestingly, SlIAA29 was induced by most treatments excluding 16 h EGTA.

With the growing popularity of internet of things (IoT) and pervasive computing, a large amount of uncertain data has been collected. Frequent itemsets mining has attracted much attention in database and data mining communities. Current methods exists some disadvantages, such as inaccurate, low efficiency, etc. To address this problem, we propose a novel approach, called uncertain pattern-slide window algorithm (UP-SW) is presented. In this algorithm, a new tree structure called USFP-tree is designed to save the redeveloped header table; the model of slide-window is adopted into the renewal process of mining result. The USFP-tree is structured based on dynamic array (ARRAY) and link information (LINK), as the slide-window slides, the mining result saved in USFP-tree is refreshed. The probabilistic frequent itemsets are obtained by traversing the final ARRAY of header table. Experimental results and theoretical analysis show that UP-SW has better performance than several other UP algorithms, especially on the mining efficiency and reducing the memory usage.

Background The formation and development of bulblets are crucial to the Lilium genus since these processes are closely related to carbohydrate metabolism, especially to starch and sucrose metabolism. However, little is known about the transcriptional regulation of both processes. To gain insight into carbohydrate-related genes involved in bulblet formation and development, we conducted comparative transcriptome profiling of Lilium davidii var. unicolor bulblets at 0 d, 15 d (bulblets emerged) and 35 d (bulblets formed a basic shape with three or four scales) after scale propagation. Results Analysis of the transcriptome revealed that a total of 52,901 unigenes with an average sequence size of 630 bp were generated. Based on Clusters of Orthologous Groups (COG) analysis, 8% of the sequences were attributed to carbohydrate transport and metabolism. The results of KEGG pathway enrichment analysis showed that starch and sucrose metabolism constituted the predominant pathway among the three library pairs. The starch content in mother scales and bulblets decreased and increased, respectively, with almost the same trend as sucrose content. Gene expression analysis of the key enzymes in starch and sucrose metabolism suggested that sucrose synthase (SuSy) and invertase (INV), mainly hydrolyzing sucrose, presented higher gene expression in mother scales and bulblets at stages of bulblet appearance and enlargement, while sucrose phosphate synthase (SPS) showed higher expression in bulblets at morphogenesis. The enzymes involved in the starch synthetic direction such as ADPG pyrophosphorylase (AGPase), soluble starch synthase (SSS), starch branching enzyme (SBE) and granule-bound starch synthase (GBSS) showed a decreasing trend in mother scales and higher gene expression in bulblets at bulblet appearance and enlargement stages while the enzyme in the cleavage direction, starch de-branching enzyme (SDBE), showed higher gene expression in mother scales than in bulblets. Conclusions An extensive transcriptome analysis of three bulblet development stages contributes considerable novel information to our understanding of carbohydrate metabolism-related genes in Lilium at the transcriptional level, and demonstrates the fundamentality of carbohydrate metabolism in bulblet emergence and development at the molecular level. This could facilitate further investigation into the molecular mechanisms underlying these processes in lily and other related species. Electronic supplementary material The online version of this article (doi:10.1186/s12870-014-0358-4) contains supplementary material, which is available to authorized users.