Cloning and Functional Analysis of BcMYB101 Gene Involved in Leaf Development in Pak Choi (Brassica rapa ssp. Chinensis)

As one of the largest transcription factor families, MYB transcription factors are widely present, and they are involved in a diverse range of physiological activities in plants, such as leaf development. GAMYB genes belong to the R2R3-MYB subfamily, which includes the MYB33/65/101 gene, and these genes are studied well in seed germination and flowering, but their roles in leaf development are poorly understood. In the current study, we isolated a GAMYB transcription factor from pak choi, BcMYB101, and analyzed its characteristics and function. The sequence structure analysis indicated that BcMYB101 has a highly conserved R2R3 DNA-binding domain in the N-terminal region and three GAMYB-specific motifs (Box1, Box2, and Box3). The expression pattern of diverse tissues revealed that BcMYB101 has a higher transcript level in the petiole, leaf, root, and floral organs. Furthermore, the expression level was significantly elevated after GA (gibberellin) treatment, suggesting that the BcMYB101 response was positively regulated by GA. Subcellular localization exhibited that BcMYB101 was only present in the nuclear region, consistent with the characterization of the transcription factor. The overexpression of BcMYB101 elucidated that BcMYB101 increased leaf number and resulted in downward-curling cauline leaves. Moreover, the virus-induced BcMYB101 silencing displayed that BcMYB101 is involved in the regulation of curly leaves. Furthermore, we discovered that BcMYB101 has two trans-activation activities and one interaction protein, BcTCH4, using a trans-activation activity assay and a yeast two-hybrid assay, respectively. In this study, we firstly isolated the BcMYB101 gene and explored its function in leaf development, thereby providing a solid foundation for further research on the regulatory mechanism of leaf shape in Brassica or other species.

Genome-wide analysis of OVATE family proteins in cucumber (Cucumis sativus L.)

Background: OVATE family proteins (OFPs) are plant-specific proteins with the conserved OVATE domain that regulating plant growth and development. Although these OFPs have been studied in several species, the biological functions of this OFP gene family remain largely unknown in cucumber (Cucumis sativus L.). Results: In this study, we identified 19 CsOFPs in cucumber. This CsOFPs are distributed on seven chromosomes and can be divided into four subgroups. Most CsOFP genes are expressed in reproductive organs although have different expression patterns. Cis-elements analysis showed that there are six kinds of hormone response elements in CsOFPs and exogenous gibberellin treatment leads to a ‘first increase then decrease’ expression pattern of CsOFP7, CsOFP11 and CsOFP12. Ectopic expression of CsOFP11 in Arabidopsis resulted in shorter and blunt siliques. Conclusions: Together, these results indicated that CsOFPs may play important roles in cucumber fruit development.

Flowering and nutritional status of Gladiolus hybridus L. ‘Black Velvet’ following gibberellin treatment

Flowering and nutritional status in Gladiolus hybridus L. ‘Black Velvet’ were assessed following gibberellic acid treatment (GA₃). Treatment were applied to corm (12–14 diameter) by soaking for 30 min in water solutions of GA₃ at 100, 350 and 600 mg/dm³with a control consisting of soaking-in water. All GA₃ treatments inhibited elongation of inflorescence shoots and stimulated spike elongation. None of the tested concentrations affected the number of developing flowers in the spike, except for the 100 mg/dm³ in the 2nd year of the study. All GA₃ treatments stimulated calcium uptake, but had no effect on the uptake of other macronutrients. All the GA₃ treatments increased manganese content in leavesbud did not affect copper content. GA₃ at 600 mg/dm³ stimulated uptake of iron and boron at 600 mg/dm³ but inhibited both at lower concentrations. Zinc uptake was stimulated at 100 mg/dm³but inhibited at higher concentration.

Effects of (S)-Carvone and Gibberellin on Sugar Accumulation in Potatoes during Low Temperature Storage

Potato tubers (Solanum tuberosum L.) are usually stored at low temperature, which can suppress sprouting and control the occurrence of diseases. However, low temperatures lead potatoes to easily suffer from cold-induced sweetening (CIS), which has a negative effect on food processing. The aim of this research was to investigate potential treatments on controlling CIS in potatoes during postharvest storage. “Atlantic” potatoes were treated with gibberellin and (S)-carvone, respectively, and stored at 4 °C for 90 days. The results showed that gibberellin can significantly accelerate sprouting and sugar accumulation by regulating expressions of ADP-glucose pyrophosphorylase (AGPase), granule-bound starch synthase (GBSS), β-amylase (BAM1/2), UDP-glucose pyrophosphorylase (UGPase) and invertase inhibitor (INH1/2) genes. The opposite effects were found in the (S)-carvone treatment group, where CIS was inhibited by modulation of the expressions of GBSS and INH1/2 genes. In summary, gibberellin treatment can promote sugar accumulation while (S)-carvone treatment has some effects on alleviating sugar accumulation. Thus, (S)-carvone can be considered as a potential inhibitor of some of the sugars which are vital in controlling CIS in potatoes. However, the chemical concentration, treatment time, and also the treatment method needs to be optimized before industrial application.

Identification and characterization of cherry (Cerasus pseudocerasus G. Don) genes in response to parthenocarpy induced by GA3 through transcriptome analysis

Fruit set after successful pollination is a key process in the production of sweet cherries, but low fruit rate is the main problem for crop production in sweet cherries. Gibberellin treatment can directly induce parthenogenesis without pollination; therefore, gibberellin treatment is a very important method to improve the fruit setting rate of sweet cherries. Exogenous gibberellin can satisfy the hormone requirement during fruit growth and development. Some related studies have mainly focused on physiological aspects, such as breeding, branching, fertilization, etc., and the molecular mechanism is not clear. In this study, we analyzed the transcriptome of ‘Meizao’ sweet cherry fruit treated with gibberellin during the anthesis and hard-core period to determine the genes associated with parthenocarpic fruit set. A total of 765 and 186 differentially expressed genes (DEGs) were found at anthesis and the hard-core stage after gibberellin 3 (GA3) treatment, respectively. The differentially expressed genes between the control and GA3 treatment showed that the GA3 response mainly included parthenocarpic fruit set and cell division. Exogenous gibberellin stimulated sweet cherry parthenocarpy and enlargement, which were verified by qRT-PCR results of related genes and the parthenocarpic fruit set and fruit size. Based on our research and previous studies on Arabidopsis thaliana, we identified the key genes associated with parthenocarpic fruit set and cell division. Briefly, we found patterns in the sweet cherry fruit setting-related DEGs, especially those associated with hormone balance, cytoskeleton formation and cell wall modification. Overall, the result provides a possible molecular mechanism regulating parthenocarpic fruit set, which is important for basic research and industrial development of sweet cherries.Highlightcherry genes in response to parthenocarpy and promote to fruit setting induced by GA3.

Features of gas exchange and use of reserve substances in pumpkin seedlings in conditions of skoto- and photomorphogenesis under the influence of gibberellin and chlormequat-chloride

We investigated the effect of gibberellin and the antigibberellic agent chlormequat-chloride on gas exchange and use of reserve substances in pumpkin seedlings during germination in the light and in the dark. We established that an artificial strengthening or growth inhibition of pumpkin seedlings in conditions of skotomorphogenesis caused an increase in of respiration intensity. Gibberellin treatment increased the proportion of assimilation processes in carbon dioxide gas exchange of seedlings, and growth inhibition by retardant caused an increase in respiratory costs when the nutrition type switches in the light from heterotrophic to autotrophic. The formation by seedlings of the demand for reserve assimilates from cotyledons was largely determined by change of activity of subapical meristems, which is manifested in the acceleration of seed germination, enhancing of histogenesis for the actions of gibberellin and in the weakening of these processes under the influence of retardants. Reserve substances used both oil and nitrogen-containing compounds. The content of protein nitrogen in pumpkin cotyledons decreased more in the light than in the dark, moreover growth inhibition by the retardant slowed down and growth increase by gibberellin accelerated this process both in conditions of photomorphogenesis and skotomorphogenesis.