Integrated Signals of Jasmonates, Sugars, Cytokinins and Auxin Influence the Initial Growth of the Second Buds of Chrysanthemum after Decapitation

Abstract

Decapitation is common in horticulture for altering plant architecture. The decapitation of chrysanthemum plants breaks apical dominance and leads to more flowers on lateral branches, resulting in landscape flowers with good coverage. We performed both third- and second-generation transcriptome sequencing of the second buds of chrysanthemum. This third-generation transcriptome is the first sequenced third-generation transcriptome of chrysanthemum, revealing alternative splicing events, lncRNAs, and transcription factors. Aside from the classic hormones, the expression of jasmonate-related genes changed because of this process. Sugars also played an important role in this process, with upregulated expression of sucrose transport-related and TPS genes. We constructed a model of the initial growth of the second buds after decapitation. Auxin export and sugar influx activated the growth of these buds, while the JA-Ile caused by wounding inhibited the expression of CycD genes from 0 h to 6 h. After wound recovery, cytokinins accumulated in the second buds and might have induced ARR12 expression to upregulate CycD gene expression from 6 h to 48 h, together with sugars. Therefore, jasmonates, cytokinins, sugars, and auxin work together to determine the fate of the buds of plants with short internodes, such as chrysanthemum.

Lighting from Top and Side Enhances Photosynthesis and Plant Performance by Improving Light Usage Efficiency

“…Moreover, the TS lighting resulted in the greatest light efficiency, which further induced well-developed terminal buds and lateral buds, causing higher bio-activities and promoting phytohormone cycles. Meanwhile, the well-developed lateral shoot preferentially receives branch-promoted hormones such as cytokinins transported from the root, thus promoting the quantity and quality of the lateral buds [ 46 , 47 , 48 ]. In addition, according to the nutrition theory that K. Gerber proposed, the well-developed bud cells rapidly grow, vigorously metabolize, and require more nutrients.…”

Side Lighting Enhances Morphophysiology by Inducing More Branching and Flowering in Chrysanthemum Grown in Controlled Environment

“…In addition, it was found that the lateral buds were able to grow when the cytokinin was applied to the inhibited lateral buds, and the apical dominance was relieved. Therefore, an inhibition of the lateral buds occurred, because they did not have enough cytokinins directed toward them [ 61 , 62 , 63 ]. In our study, the chrysanthemum plants grown using the side lighting lacked light from the top and experienced a stunted development of the terminal bud.…”

H2O2 promotes trimming-induced tillering by regulating energy supply and redox status in bermudagrass

“…In tobacco, the expression of sucrose biosynthesis genes, SPS and sucrose phosphate phosphatase ( SPP ), is up-regulated after topping ( Wang et al, 2018 ). Similarly, after the topping of chrysanthemums, the expression levels of sucrose carriers ( SUCs ) and Sugars Will Eventually be Exported Transporters ( SWEETs ) increased ( Sun et al, 2021 ). Meanwhile, the sucrose content increased significantly after trimming ( Mason et al, 2014 ).…”