Identification of MicroRNAs in Taxillus chinensis (DC.) Danser Seeds under Cold Stress

Abstract

Taxillus chinensis (DC.) Danser, a parasitic plant that belongs to the Loranthaceae family, has a long history of being used in the Chinese medicine. We observed that the loranthus seeds were sensitive to temperature and could lose viability below 0°C quickly. Thus, we performed small RNA sequencing to study the microRNA (miRNA) regulation in the loranthus seeds under cold stress. In total, we identified 600 miRNAs, for the first time, in the loranthus seeds under cold stress. Then, we detected 224, 229, and 223 miRNAs ( TPM > 1 ) in A0 (control), A1 (cold treatment for 12 h at 0°C), and A2 (cold treatment for 36 h at 0°C), respectively. We next identified 103 differentially expressed miRNAs (DEmiRs) in the loranthus seeds in response to cold. Notably, miR408 was upregulated during the cold treatment, which can regulate genes encoding phytocyanin family proteins and phytophenol oxidases. Some DEmiRs were specific to A1 and may function in early response to cold, such as gma-miR393b-3p, miR946, ath-miR779.2-3p, miR398, and miR9662. It is interesting that ICE3, IAA13, and multiple transcription factors (e.g., WRKY and CRF4 and TCP4) regulated by the DEmiRs have been reported to respond cold in other plants. We further identified 4, 3, and 4 DEmiRs involved in the pathways “responding to cold,” “responding to abiotic stimulus,” and “seed development/germination,” respectively. qRT-PCR was used to confirm the expression changes of DEmiRs and their targets in the loranthus seeds during the cold treatment. This is the first time to study cold-responsive miRNAs in loranthus, and our findings provide a valuable resource for future studies.

On Overview Of Bioactive Compounds, Biological And Pharmacological Effects Of Mistletoe (Viscum Album L)

“…Mistletoe was later discovered for its miraculous effects, and traditional medicine spread it over time to many parts of the world, in particular, V. album L. and Loranthus (Taxillus Chinensis (DC.) Danser) [28,29]. The latter belongs to the family Loranthaceae, distributed mainly in southern and southwestern China, is known as "Sang Ji Sheng", and its leaves and stems have a long history in traditional Chinese medicine, is used to treat rheumatism, arrhythmia, angina pectoris, hypertension, stroke [28].…”

“…Danser) [28,29]. The latter belongs to the family Loranthaceae, distributed mainly in southern and southwestern China, is known as "Sang Ji Sheng", and its leaves and stems have a long history in traditional Chinese medicine, is used to treat rheumatism, arrhythmia, angina pectoris, hypertension, stroke [28]. V. album L. also has a long traditional history of about 100 years, used in German-speaking countries in cancer treatment therapy [29].…”

A De Novo Transcriptome Analysis Identifies Cold-Responsive Genes in the Seeds of Taxillus chinensis (DC.) Danser

“…For the cold treatment experiment, we selected 300 T. chinensis seeds with similar appearances, including sizes, weights, and health conditions. We observed that the T. chinensis seeds were sensitive to temperature and that 0°C was a suitable temperature to study the cold-responsive genes [ 23 ]. The seeds were divided into three groups—no treatment (A0) and cold treatment for 12 h (A1), 24 h (A2), and 36 h (A3).…”

“…Previously, our lab identified genes that are expressed in response to water loss in T. chinensis seeds [ 22 ], such as RD22, HSP, and various TFs (MYB, WRKY, and ethylene-responsive transcription factors), and reported the regulatory miRNAs in T. chinensis seeds in response to cold [ 23 ], such as miR408, miR393b, miR946, ath-miR779.2, miR398, and miR9662. Interestingly, ICE3, IAA13, and multiple TFs (e.g., WRKY and CRF4 and TCP4) were shown to be targets of the dysregulated miRNAs identified in the T. chinensis seeds under cold stress [ 23 ]. In the present study, we used the same material as the miRNA study and investigated changes in gene expression changes in T. chinensis seeds in response to cold using transcriptome sequencing technology.…”

Chromosome-Level Genome Assembly of the Hemiparasitic Taxillus chinensis (DC.) Danser

“…Besides, T. chinensis can only be propagated by seed, and its seed is generally recalcitrant, exhibiting sensitivities to both dehydration and low temperature ( Pan et al 2021 ), which ultimately hinder the species’ utilization. Previous transcriptomic and proteomic studies have investigated the molecular mechanisms associated with the dehydration tolerance of T. chinensis ( Wei et al 2017 ; Pan et al 2021 ), and cold stress-related differentially expressed microRNAs (miRNAs) have also been reported ( Fu et al 2021 ). However, despite the insight these studies have provided into the recalcitrance, the whole-genome sequence of T. chinensis is still needed to fully understand the molecular mechanisms involved in the species’ seed recalcitrance.…”