Female inflorescence is the primary output of medical Cannabis. It contains hundreds of cannabinoids that accumulate in the glandular trichomes. However, little is known about the genetic mechanisms governing Cannabis inflorescence development. In this study, we reported the map-based cloning of a gene determining the number of inflorescences per branch. We named this gene CsMIKC1 since it encodes a transcription factor that belongs to the MIKC-type MADS subfamily. Constitutive overexpression of CsMIKC1 increases inflorescence number per branch, thereby promoting flower production as well as grain yield in transgenic Cannabis plants. We further identified a plant-specific transcription factor, CsBPC2, promoting the expression of CsMIKC1. CsBPC2 mutants and CsMIKC1 mutants were successfully created using the CRISPR-Cas9 system; they exhibited similar inflorescence degeneration and grain reduction. We also validated the interaction of CsMIKC1 with CsVIP3, which suppressed expression of four inflorescence development-related genes in Cannabis. Our findings establish important roles for CsMIKC1 in Cannabis, which could represent a previously unrecognized mechanism of inflorescence development regulated by ethylene.

Graphene oxide (GO) is widely used in various scientific fields, including biochemistry and environmental and plant science, because of its unique physicochemical properties. However, there is limited knowledge about the influence of GO on the growth and cadmium (Cd) tolerance of plants used for environmental remediation. The regulation of GO nanosheets on Cd tolerance in jute ( Corchorus olitorius L.) and the toxicity responses of the plant were investigated. Jute seedlings were cultivated in a Cd-contaminated aquatic system in the presence of GO at different concentrations (5, 10, and 20 mg/L). Several parameters, including dry biomass, chlorophyll contents, reactive oxygen species level, and antioxidant enzyme activities, were evaluated in this work. The results suggest that the effects of GO exposure on plant Cd tolerance are concentration dependent; at low concentrations, GO could promote the growth of jute and stimulate the activities of antioxidant enzymes and reduce oxidative stress to facilitate Cd uptake in jute seedlings and improve Cd tolerance. However, GO at high concentrations could inhibit plant growth, decrease Cd uptake, and increase oxidative stress. This study develops a possible application of GO nanosheets for Cd remediation at low concentrations; however, it is still in the early phases of exploration. Furthermore, the potential risks of releasing high concentrations of GO require further research.