Dendrobium catenatum, an epiphytic and lithophytic species, suffers frequently from perennial shortage of water in the wild. The molecular mechanisms of this orchid’s tolerance to abiotic stress, especially drought, remain largely unknown. It is well-known that CBL-interacting protein kinase (CIPKs) proteins play important roles in plant developmental processes, signal transduction, and responses to abiotic stress. To study the CIPKs’ functions for D. catenatum, we first identified 24 CIPK genes from it. We divided them into three subgroups, with varying intron numbers and protein motifs, based on phylogeny analysis. Expression patterns of CIPK family genes in different tissues and in response to either drought or cold stresses suggested DcaCIPK11 may be associated with signal transduction and energy metabolism. DcaCIPK9, -14, and -16 are predicted to play critical roles during drought treatment specifically. Furthermore, transcript expression abundances of DcaCIPK16 showed polar opposites during day and night. Whether under drought treatment or not, DcaCIPK16 tended to emphatically express transcript1 during the day and transcript3 at night. This implied that expression of the transcripts might be regulated by circadian rhythm. qRT-PCR analysis also indicated that DcaCIPK3, -8, and -20 were strongly influenced by circadian rhythmicity. In contrast with previous studies, for the first time to our knowledge, our study revealed that the major CIPK gene transcript expressed was not always the same and was affected by the biological clock, providing a different perspective on alternative splicing preference.

Background: Flower buds of Anthurium andraeanum frequently cease to grow and abort during the early flowering stage, resulting in prolonged planting times and increased commercialization costs. Nevertheless, limited knowledge exists of the mechanism of flower development after initiation in A. andraeanum. Results: In this study, the measurement of carbohydrate flow and intensity between leaves and flowers during different growth stages showed that tender leaves are strong sinks and their concomitant flowers are weak ones. This suggested that the tender leaves compete with their concomitant flower buds for carbohydrates during the early growth stages, potentially causing the abortion of the flower buds. The analysis of transcriptomic differentially expressed genes suggested that genes related to sucrose metabolism and auxin response play an important role during flower bud development. Particularly, co-expression network analysis found that AaSPL12 is a hub gene engaged in flower development by collaborating carbohydrate and auxin signals. Yeast Two Hybrid assays revealed that AaSPL12 can interact with AaARP, a protein that serves as an indicator of dormancy. Additionally, the application of exogenous IAA and sucrose can suppress the expression of AaARP, augment the transcriptional abundance of AaSPL12, and consequently expedite flower development in Anthurium andraeanum. Conclusions: Collectively, our findings indicated that the combination of auxin and sugar signals could potentially suppress the repression of AaARP protein to AaSPL12, thus advancing the development of flower buds in Anthurium andraeanum.

The chloroplast genome of Anthurium andraeanum Linden 1877 was assembled and analyzed in this study. The genome size is 162,560 bp, of which contains a large single-copy (LSC) region with 88,814 bp, a small single-copy (SSC) region with 22,856 bp, and two inverted repeat regions (IRA and IRB) with 25,445 bp, respectively. The plastome contains 124 genes, including 80 protein-coding genes, 37 tRNAs, six rRNAs and one pseudogene. Phylogenetic analysis indicated that A. andraeanum is a member of Pothoideae and sister to A. huixtlense.

We would like to submit several corrections to our published paper “Circadian Regulation of Alternative Splicing of Drought-Associated CIPK Genes in Dendrobium catenatum (Orchidaceae)”

Tropical ornamental Anthurium andraeanum requires substantial electrical heating for overwintering when cultivated in greenhouses in subtropical regions, making cold tolerance improvement a key factor for cost reduction. However, whether exogenous 6-Benzylaminopurine (6-BA) can enhance cold hardiness in Anthurium and its underlying mechanisms remain unclear. In this study, we conducted a controlled experiment to compare the physiological and biochemical responses of A. andraeanum ‘Alabama’ subjected to low-temperature stress following foliar application of 6-BA versus water. Our results show that, compared with water treatment, 6-BA application was associated with better preservation of subcellular structural integrity, higher proline accumulation, lower hydrogen peroxide content, decreased relative electrical conductivity, increased leaf fresh weight, dry weight, and area along with reduced water content, and lower stomatal density. These findings suggest that, under defined low-temperature conditions, 6-BA is associated with enhanced physiological performance in A. andraeanum, potentially through coordinated effects on subcellular stability, osmotic adjustment, reactive oxygen species accumulation, leaf morphology and water metabolism, and stomatal density. This work provides a theoretical basis and technical reference for cold-tolerant cultivation of Anthurium.

Paeonia suffruticosa cv. ‘Yu Luo Chun’ is an important representative of the peony groups from the Jiangnan region of China. However, little is known about the genetic basis of chloroplast genome phylogeny and the adaptive evolution of this group. In this study, high-throughput sequencing technology was used to sequence the complete chloroplast genome of leaves, and sequence assembly, annotation and feature analysis were performed by bioinformatics analysis methods. The results showed that the chloroplast genome of P. suffruticosa cv. ‘Yu Luo Chun’ exhibited a typical tetrad structure with a total length of 152,596 bp, including a large single-copy (LSC) region, a small single-copy (SSC) region, and two inverted repeats (IRs) whose lengths were 84,272 bp, 17,044 bp and 25,640 bp, respectively. A total of 126 genes were annotated, including 85 protein-coding genes, 37 tRNA genes and 4 rRNA genes. Bioinformatics analysis showed that a total of 71 simple sequence repeats (SSRs) were searched in the chloroplast genome, of which the numbers of mononucleotide, dinucleotide, trinucleotide and tetranucleotide repeat motifs were 47, 12, 7 and 5, respectively, and no pentanucleotide or hexanucleotide repeat motifs were found. The chloroplast genome prefers to end in A/T, among which leucine (Leu) is the most frequently used, while cysteine ​​(Cys) is the least frequently used. Highly differentiated regions, such as rpoC1, petB, rsp16, rps19, clpP, ccsA, ycf1, ndhF-trnL, ndhD-psaC and trnV-rps12, were identified as DNA barcodes and potential genetic markers for interspecies relationships. We compared the gene selection pressure and identified 5 genes, ndhF, petB, petD, rpoA and ycf2 that were positively selected, and these genes have important contributions to the adaptive evolution. The chloroplast genome sequences of 18 species, including P. suffruticosa cv. ‘Yu Luo Chun’, were clustered by the nearest neighbour combination method and the maximum likelihood method. Both methods gave the same result and indicated that this cultivar has a relatively close kinship with P. qiui and P. rockii. The results provide important references for species identification, genetic diversity analysis and systematic taxonomic research between P. suffruticosa cv. ‘Yu Luo Chun’ and other Paeonia species.