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Some members of the CYP51G subfamily has been shown to be obtusifoliol 14α‐demethylase, key enzyme of the sterol and brassinosteroid (BR) biosynthesis, which mediate plant development and response to stresses. However, little is known about the functions of CYP51H subfamily in rice. Here, OsCYP51H3, an ortholog of rice OsCYP51G1 was identified. Compared with wild type, the mutants oscyp51H3 and OsCYP51H3‐RNAi showed dwarf phenotype, late flowering, erected leaves, lower seed‐setting rate, and smaller and shorter seeds. In contrast, the phenotypic changes of OsCYP51H3‐OE plants are not obvious. Metabolomic analysis of oscyp51H3 mutant indicated that OsCYP51H3 may also encode an obtusifoliol 14α‐demethylase involved in phytosterol and BR biosynthesis, but possibly not that of triterpenes. The RNA‐seq results showed that OsCYP51H3 may affect the expression of a lot of genes related to rice development. These findings showed that OsCYP51H3 codes for a putative obtusifoliol 14α‐demethylase involved in phytosterol and BR biosynthesis, and mediates rice development. [ABSTRACT FROM AUTHOR]

Siegesbeckia orientalis L. was identified as a novel Cd-hyperaccumulator and valuable phytoremediation material. However, the molecular mechanisms underlying Cd accumulation in S. orientalis are largely unknown. In this study, RNA-Seq analysis was performed to study the Cd-accumulating mechanisms in its roots with or without Cd treatment. The RNA-seq analysis generated 312 million pairs of clean reads and 78G sequencing data. De novo transcriptome assembly produced 355,070 transcripts with an average length of 823.59 bp and 194,207 unigenes with an average length of 605.68 bp. Comparative transcriptome analyses identified a large number of differentially expressed genes in roots under Cd stress, and functional annotation suggested that S. orientalis utilizes various biological pathways involving many gene networks working simultaneously to cope with the stress. This study revealed that four biological pathways were mainly involved in S. orientalis tolerance to Cd stress, including reactive oxygen species scavenging, phenylpropanoid biosynthesis pathway, Cd absorption and transport, and ABA signaling pathway. The genes related to photosynthesis and heavy metal transport are likely the potential candidates and could be further investigated to determine their roles in Cd tolerance in S. orientalis roots. These findings will be useful to understand the Cd accumulation mechanisms in S. orientalis and facilitate the study of phytoremediation at the molecular level in plants. [ABSTRACT FROM AUTHOR]

Cuticular wax forms a hydrophobic layer covering aerial plant organs and acting as a protective barrier against biotic and abiotic stresses. Compared with well-known wax biosynthetic pathway, molecular regulation of wax biosynthesis is less known. Here, we show that rice O s WS 1, a member of the membrane-bound O-acyl transferase gene family, involved in wax biosynthesis and was regulated by an osa-mi R 1848. Os WS 1-tagged green fluorescent protein localized to the endoplasmic reticulum (ER). Compared with wild-type rice, O s WS 1 overexpression plants displayed a 3% increase in total wax, especially a 35% increase in very long-chain fatty acids, denser wax papillae around the stoma, more cuticular wax crystals formed on leaf and stem surfaces, pollen coats were thicker and more seedlings survived after water-deficit treatment. In contrast, O s WS 1-RNAi and osa-mi R 1848 overexpression plants exhibited opposing changes. Gene expression analysis showed that overexpression of osa-mi R 1848 down-regulated O s WS 1 transcripts; furthermore, expression profiles of O s WS 1 and osa-mi R 1848 were inversely correlated in the leaf, panicle and stem, and upon water-deficit treatment. These results suggest that O s WS 1 is regulated by osa-mi R 1848 and participates in cuticular wax formation. [ABSTRACT FROM AUTHOR]

Phytosterols are membrane components or precursors for brassinosteroid ( BR) biosynthesis. As they cannot be transported long distances, their homeostasis is tightly controlled through their biosynthesis and metabolism. However, it is unknown whether micro RNAs are involved in their homeostatic regulation., Rice ( Oryza sativa) plants transformed with microRNA osa-miR1848 and its target, the obtusifoliol 14α-demethylase gene, Os CYP51G3, were used to investigate the role of osa-miR1848 in the regulation of phytosterol biosynthesis., osa-miR1848 directs Os CYP51G3 mRNA cleavage to regulate phytosterol and BR biosynthesis in rice. The role of Os CYP51G3 as one of the osa-miR1848 targets is supported by the opposite expression patterns of osa-miR1848 and Os CYP51G3 in transgenic rice plants, and by the identification of Os CYP51G3 mRNA cleavage sites. Increased osa-miR1848 and decreased Os CYP51G3 expression reduced phytosterol and BR concentrations, and caused typical phenotypic changes related to phytosterol and BR deficiency, including dwarf plants, erect leaves, semi-sterile pollen grains, and shorter cells. Circadian expression of osa-miR1848 regulated the diurnal abundance of Os CYP51G3 transcript in developing organs, and the response of Os CYP51G3 to salt stress., We propose that osa-miR1848 regulates Os CYP51G3 expression posttranscriptionally, and mediates phytosterol and BR biosynthesis. osa-miR1848 and OsCYP51G3 might have potential applications in rice breeding to modulate leaf angle, and the size and quality of seeds. [ABSTRACT FROM AUTHOR]

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers. [ABSTRACT FROM AUTHOR]