Identification of drought-responsive miRNAs and physiological characterization of tea plant (Camellia sinensis L.) under drought stress

Abstract

BackgroundDrought stress is one of the major natural challenges in the main tea-producing regions of China. The tea plant (Camellia sinensis) is a traditional beverage plant whose growth status directly affects tea quality. Recent studies have revealed that microRNAs (miRNAs) play key functions in plant growth and development. Although some miRNAs have been identified in C. sinensis, little is known about their roles in the drought stress response of tea plants.ResultsPhysiological characterization of Camellia sinensis ‘Tieguanyin’ under drought stress showed that the malondialdehyde concentration and electrical conductivity of leaves of drought-stressed plants increased when the chlorophyll concentration decreased under severe drought stress. We sequenced four small-RNA (sRNA) libraries constructed from leaves of plants subjected to four different treatments, normal water supply (CK); mild drought stress (T1); moderate drought stress (T2) and severe drought stress (T3). A total of 299 known mature miRNA sequences and 46 novel miRNAs were identified. Gene Ontology enrichment analysis revealed that most of the differentially expressed-miRNA target genes were related to regulation of transcription. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the most highly enriched pathways under drought stress were D-alanine metabolism, sulfur metabolism, and mineral absorption pathways. Real-time quantitative PCR (qPCR) was used to validate the expression patterns of 21 miRNAs (2 up-regulated and 19 down-regulated under drought stress). The observed co-regulation of the miR166 family and their targets ATHB-14-like and ATHB-15-like indicate the presence of negative feedback regulation in miRNA pathways.ConclusionsAnalyses of drought-responsive miRNAs in tea plants showed that most of differentially expressed-miRNA target genes were related to regulation of transcription. The results of study revealed that the expressions of phase-specific miRNAs vary with morphological, physiological, and biochemical changes. These findings will be useful for research on drought resistance and provide insights into the mechanisms of drought adaptation and resistance in C. sinensis.Electronic supplementary materialThe online version of this article (10.1186/s12870-017-1172-6) contains supplementary material, which is available to authorized users.

Integrated sRNAome and RNA-Seq Analysis Reveals miRNA Effects on Betalain Biosynthesis in Pitaya

“…miRNAs regulate their target genes by mRNA at the post-transcriptional level via the RNAinduced silencing complex (RISC) by binding with the Argonaute (AGO) protein to cleavage target mRNA or repress translation of target mRNA [1]. miRNAs play vital roles in plant growth and development, (a)biotic stress response, post-transcriptional regulation, and pigment regulation [2][3][4]. miRNAs are involved in chlorophyll, carotenoid, and anthocyanin biosynthesis.…”

“…miRNAs are involved in chlorophyll, carotenoid, and anthocyanin biosynthesis. miRNAs can regulate coloration and chlorophyll accumulation [3,[5][6][7]. Overexpression of osa-miR171b by an arti cial miRNA could enhance chlorophyll accumulation in rice leaves [7].…”

The ghr-miR164 and GhNAC100 module participates in cotton plant defence against Verticillium dahliae

“…As shown in Supplementary Table S2, the expression levels of the miRNAs ranged widely from tens of thousands of sequence reads to fewer than 100. The MIR166 had the most abundant expression and reached over 10000 TPM clean reads, which are highly conserved in mosses, eudicots and monocots (Arazi et al ., 2005; Barik et al ., 2014; Guo et al , 2017; Shi et al ., 2017; Yip et al , 2016). In addition, among the 46 miRNA families, 21 and 24 nt long miRNAs represented the majority in size, reaching 38.03% and 32.39%, respectively, followed by the 20 nt long miRNAs (14.08%) (Supplementary Table S3).…”

ФИЗИОЛОГИЧЕСКИЕ И ГЕНЕТИЧЕСКИЕ МЕХАНИЗМЫ ОТВЕТА ЧАЙНОГО РАСТЕНИЯ Camellia sinensis (L.) Kuntze НА ЗАСУХУ

“…Эти вещества относятся к трем основным классам: аминокислотам (глутамин, пролин, глицин-бетаин, карнитин), сахарам (крахмал, ди-и моносахариды) и полиолам (маннитол, сорбитол) (43). Среди аминокислот особенно важен пролин (44), который синтезируется из глутамата (с участием фермента пирролин-5-карбоксилатсинтазы) или орнитина (26,43). Накопление пролина сопровождается предотвращением денатурации белка, сохранением структуры и активности ферментов, а также защитой мембран от повреждения АФК при дефиците влаги и высокой солнечной активности.…”

“…У чая выявлены 62 микроРНК, которые участвуют в ответе на засуху через регуляцию транскрипции и подавление трансляции. Установлено, что экспрессия микроРНК варьирует в зависимости от силы стресс-фактора и проявляется в виде морфологических, физиологических и биохимических изменений (77).…”