Taro (Colocasia esculenta) is an important tuber crop and staple food. Taro corms have higher nutritional value and starch contents as compared to most of the other root/tuber crops. However, the growth and development of the taro rhizome have not been critically examined in terms of transcriptomic signatures in general or specific to carbohydrates (starch and sucrose) accumulation. In current study, we have conducted a comprehensive survey of transcripts in taro corms aged 1, 2, 3, 4, 5, and 8 months. In this context, we have employed a whole transcriptome sequencing approach for identification of mRNAs, CircRNAs, and miRNAs in corms and performed functional enrichment analysis of the screened differentially expressed RNAs. A total of 11,203 mRNAs, 245 CircRNAs, and 299 miRNAs were obtained from six developmental stages. The mRNAs included 139 DEGs associated with 24 important enzymes of starch and sucrose metabolism. The expression of genes encoding key enzymes of starch and sucrose metabolism pathway (GBSS, AGPase, UGPase, SP, SSS, βFRUCT and SuSy) demonstrated significant variations at the stage of 4 months (S4). A total of 191 CircRNAs were differentially expressed between the studied comparisons of growth stages and 99 of these were associated with those miRNA (or target genes) that were enriched in starch and sucrose metabolism pathway. We also identified 205 miRNAs including 46 miRNAs targeting DEGs enriched in starch and sucrose biosynthesis pathway. The results of current study provide valuable resources for future exploration of the molecular mechanisms involved in the starch properties of Taro.

Taro is a widely utilized starch resource plant. It is essential to quantify the expression levels of functional genes associated with taro growth using real-time quantitative polymerase chain reaction (RT-qPCR). However, to obtain reliable RT-qPCR results, appropriate reference genes (RGs) are required for data normalization. In this study, we screened seven novel candidate RGs using transcriptome datasets from taro, encompassing data from growth corms and various tissues. The expression stability of these seven new RGs, along with the commonly used RGs Actin, EF1-α, and β-tubulin, was assessed using Delta Ct, BestKeeper, geNorm, and NormFinder algorithms. Furthermore, we conducted a comprehensive analysis using the RefFinder program and validated the results using the target gene, CeAGPL1. The findings revealed that ACY-1 and PIA2 were the optimal multiple RGs for normalization during corm growth, while COX10 and Armc8 were suitable for samples including various types of tissues. Furthermore, we found three RGs, Armc8, COX10 and CCX4L, were the optimal RGs for drought stress. This study assessed the suitability of RGs in taro for the first time. The identified RGs provide valuable resources for studying corm growth, diverse tissues, and drought stress. This study contributes to the advancement of our understanding of the underlying mechanisms that govern the growth of taro.

Colocasia esculenta ranks as the fifth most important tuber crop and is known for its high nutritional and medicinal value. However, there is no research on its mitochondrial genome, hindering in-depth exploration of its genomic resources and genetic relationships. Using second- and third-generation sequencing technologies, we assembled and annotated the mitogenome of C. esculenta. Its mitogenome mainly consists of five circular DNA molecules, with a total length of 594,811 bp and a GC content of 46.25%. A total of 55 genes, 157 simple sequence repeats, 29 tandem repeat sequences, 202 dispersed repeat sequences, and 625 RNA editing sites were detected. Most protein-coding genes use ATG as the start codon, and the third position of the codon tends to be A or T (U). GAA, AUU, and UUU are the most common codons in C. esculenta mitochondria. Finally, based on 28 representative plant species, a phylogenetic tree was constructed, revealing a close relationship between C. esculenta and Araceae. This study provides comprehensive information on C. esculenta, laying a foundation for crop genetics and molecular breeding.

Getting males from a hermaphrodite population. This is a modified version of protocol originally written by Michael Koelle at Yale University.

The global significance of Colocasia esculenta, a tuber crop rich in nutritional value and starch, prompts further investigation into its corm development. Background: Previous studies have focused on starch accumulation within the tubers, yet the genetic and proteomic basis of corm expansion remains largely unexplored. This study aims to elucidate the key genes and proteins involved in this process. Methods: We selected ‘Lipu Taro No.1’ and conducted a longitudinal starch content analysis, full-length transcriptome sequencing, and a proteomic analysis during three distinct stages of corm development. Results: Our findings reveal a significant increase in both amylose and amylopectin contents as the corm develops, indicating the temporal regulation of starch biosynthesis. The integration of transcriptome and proteomic data identified differentially expressed genes and proteins associated with starch and sucrose metabolism, as well as plant hormone signal transduction. Conclusions: This study delineates a temporal gene expression pattern that is crucial for starch synthesis and provides insights into the regulatory mechanisms controlling corm expansion and starch deposition, offering valuable references for future molecular breeding strategies to enhance taro yield and quality.