B-box zinc finger proteins contain one or two B-box domains, and sometimes, a CCT domain, which are involved in many biological processes, such as photomorphogenesis, flowering, anthocyanin synthesis and abiotic stress resistance. But the BBX gene family in pineapple has not been systematically studied. Nineteen BBX genes were detected in pineapple genome and divided into five groups according to phylogenetic analysis. The results of transcriptome analysis and RT-qPCR showed that most of AcBBX members were highly expressed during the flowering process, indicating that AcBBX gene may be involved in flower bud differentiation and morphogenesis. Transcriptional activation analysis showed that AcBBX6 and AcBBX18 had transcriptional activity and were located in the nucleus. Overexpression of AcBBX18 promoted flowering in Arabidopsis thaliana. These results provided a basis for further study functions and regulatory mechanism of BBX members in pineapple floral induction and flower development.

Sweet potato (Ipomoea batatas (L.) Lam.) is served as an important root crop worldwide due to its high yield, strong adaptability and nutrient richness. Sweet potato has played a significant role in ensuring food security and family income opportunities for local populations in China for years of experience. The storage roots, which provide abundant nutrition and health benefits to people, are the mainly harvested and consumed parts of sweet potato. However, after harvest, physiological disorders, such as sprouting, mechanical injury and infectious postharvest diseases, increase the magnitude of sweet potato root quality decline and nutritional compound losses. Ethylene and 1-methylcyclopropene (1-MCP) were considered to be effective commercial treatments in sweet potato postharvest. Exogenous ethylene and 1-MCP treatment could successfully inhibit root sprouts and reduce rot decay without affecting the storage quality of sweet potato. This review aims to summarize the latest available information on the effects of ethylene and 1-MCP with respect to enhancing or impairing sweet potato root quality. A better understanding of the influence of ethylene and 1-MCP on root quality parameters will be useful to further explore the role and mechanisms of action of ethylene in regulating the postharvest storage of sweet potato roots and contributions to technological development and innovation.

Trihelix transcription factors with helix–loop–helix–loop–helix characteristics are essential in plant growth, development, and response to adversity. Several potential functions of Trihelix have been studied in multiple plant species, but little is known about the features and functions of Trihelix genes in pineapple. In this study, 23 Trihelix members were identified and classified into 5 groups and were unevenly distributed in 17 chromosomes of pineapple. The results revealed that six fragment duplication events and one tandem duplication event were found through gene duplication analysis. Moreover, 4, 10, 21, and 23 homologous gene pairs were found between pineapple and Arabidopsis, grape, banana, and rice, respectively. The promoters of Trihelix have many cis-elements, especially in light and hormone response. The expression characteristics of AcTrihelix members showed obvious tissue specificities in different tissues. The expressions of AcTrihelix3, AcTrihelix8, AcTrihelix16, AcTrihelix19, AcTrihelix20, and AcTrihelix23 were maintained at high levels during the late stage of flower bud development. In floral organs, the expression of different members was very different. In conclusion, some AcTrihelix members may play important roles during the floral development of pineapple, and they provide resources for further studies of the function of Trihelix and the molecular mechanism during pineapple flower formation.

During the ripening of litchi (Litchi chinensis Sonn.) fruit, anthocyanin biosynthesis is crucial in providing vibrant coloring. Previous studies on anthocyanin-related transcription factors have made significant discoveries relating to plants. However, the role of the SQUAMOSA promoter-binding protein-like (SPL) transcription factors in anthocyanin biosynthesis has rarely been studied in litchi. SPL genes are widely involved in the developmental mechanisms of plants. In this study, a total of 17 SPL genes have been identified from the litchi genome. Phylogenetic analysis revealed that these genes were divided into eight groups (Group I-VIII). Analysis of gene structure conserved domains, conserved motifs, and miR156 target prediction showed that LcSPLs were highly conserved during evolution. RNA-seq analysis of litchi revealed that six LcSPL genes have a role in regulating anthocyanin biosynthesis. Further, weighted correlation network analysis (WGCNA) revealed LcSPL7’s role in anthocyanin synthesis and chlorophyll degradation in litchi fruit ripening. These findings collectively suggest that the LcSPL gene family plays an essential role in anthocyanin biosynthesis in litchi pericarp. In summary, comprehensive bioinformatics analysis of the SPL family expands our understanding of anthocyanin synthesis in litchi pericarp.

Pineapple (Ananas comosus (L.) Merr.) is an economically significant and delicious tropical fruit. Pineapple commercial production faces severe decline due to abiotic stresses, which affect the development and quality of pineapple fruit. Heat shock protein 70 (HSP70) plays an essential role in abiotic stress tolerance. However, the pineapple HSP70 family identification and expression analysis in response to abiotic stresses has not been studied. To explore the functional role of AcHSP70, different abiotic stress treatments were applied to pineapple cultivar “Bali” seedlings. A total of 21 AcHSP70 members were identified in the pineapple genome. The identified genes were classified into four subfamilies (I–IV) using phylogenetic analysis. The AcHSP70 family is expressed under different stress conditions. Quantitative real time polymerase chain reaction (qRT-PCR) revealed the expression pattern of the AcHSP70 family under cold, drought, salt, and heat stress. The expression level of genes such as AcHSP70-2 increased under heat, cold, and drought stress, while the expression level of genes such as AcHSP70-3 decreased under salt stress. Furthermore, the expression profile of AcHSP70s in different tissues and development stages was analyzed using transcriptome analysis. The HSP70 genes exhibited unique expression patterns in pineapple tissue at different developmental stages. The study therefore provides a list of HSP70 genes with substantial roles in abiotic stress response and valuable information for understanding AcHSP70 functional characteristics during abiotic stress tolerance in pineapple.

Litchi exhibits a large number of flowers, many flowering batches, and an inconsistent ratio of male and female flowers, frequently leading to a low fruit-setting rate. Floral sexual differentiation is a crucial phase in perennial trees to ensure optimal fruit production. However, the mechanism behind floral differentiation remains unclear. The objective of the study was to identify the role of auxin in floral differentiation at the transcriptional level. The results showed that the ratio of female flowers treated with naphthalene acetic acid (NAA) was significantly lower than that of the control stage (M0/F0). The levels of endogenous auxin and auxin metabolites were measured in male and female flowers at different stages of development. It was found that the levels of IAA, IAA-Glu, IAA-Asp, and IAA-Ala were significantly higher in male flowers compared to female flowers. Next-generation sequencing and modeling were employed to perform an in-depth transcriptome analysis on all flower buds in litchi ‘Feizixiao’ cultivars (Litchi chinensis Sonn.). Plant hormones were found to exert a significant impact on the litchi flowering process and flower proliferation. Specifically, a majority of differentially expressed genes (DEGs) related to the auxin pathway were noticeably increased during male flower bud differentiation. The current findings will enhance our comprehension of the process and control mechanism of litchi floral sexual differentiation. It also offers a theoretical foundation for implementing strategies to regulate flowering and enhance fruit production in litchi cultivation.