[Objective] The study aims to understand the distribution of Anthocerotophyta in Xizang, add new materials for the research of moss plants in Xizang, and provide essential basic data for the conservation of bryophyte diversity in China. [Methods] The research materials of Anthocerotophyta were obtained from field investigation. The species diversity was determined through indoor morphological observation and literature review. [Results] The collected specimens of corneophytes, growing in the meadow at the edge of the spruce forest and autochthonism in Linzhi, were analyzed by classical taxonomic method combined with observation of the morphological structure of plant body and sporophyte. Two new records, Anthoceros punctatus L. and Phaeoceros laevis (L.) Prosk., were identified. [Conclusion] A . punctatus L.and P . laevis (L.) Prosk. were recorded for the first time in Xizang.
[Objective] Under the background of climate warming and changing precipitation pattern, how to ensure the sustainable and stable function of grassland ecosystem and their ability to provide ecological services depends on comprehensive study of the relationship between biodiversity and productivity and its stability. This is also one of the central focus in the study of global change ecology. [Reviews] This paper systematically reviews the latest research progress in global change ecology at home and abroad, focusing on the following three aspects: First, we provide an overview of how species diversity affects productivity and its stability, as well as the potential mechanisms underlying these effects. Second, we provide a detailed overview of recent studies on the relationship between plant diversity and productivity and its stability in response to climate warming and changing precipitation, based on field experiments and other methods. Finally, we explore how dynamic changes in plant species composition play a crucial role in regulating the stability of community productivity. [Prospect] This paper puts forward some suggestions on the key issues and future research directions of plant community stability and its mechanism.
[Objective] This study aims to reveal the molecular mechanism of anthocyanin synthesis and coloration in the spathe of Zantedeschia hybrida regulated by exogenous sugars, which can provide theoretical basis for the development of postharvest preservation technology of cut flowers. [Methods] The cut flowers of pink Z. hybrida were used as materials to study the effects of glucose, mannose, mannitol, and GHG (mix of glucosamine hydrochloride and glucose) on the color phenotype, anthocyanin content, and expression of the genes related to their synthesis at 333 mmol/L, 499 mmol/L, and 666 mmol/L, respectively. [Results] (1) Treatment of glucose, mannose, and mannitol reduced spathe brightness, increased redness and chroma, and promoted anthocyanin accumulation. GHG treatment reduced spathe redness and chroma, and decreased anthocyanin accumulation. (2) 499 mmol/L mannitol promoted the expression of anthocyanin synthesis-related genes, including ZhMYB, ZhCHS, ZhCHI, ZhF3H , ZhF3'H , ZhDFR, and ZhANS, while glucose promoted the expression of six genes except ZhANS. Expression of ZhMYB, ZhCHS, and ZhCHI under GHG treatment was lower than glucose alone. [Conclusion] Appropriate amount of exogenous glucose, mannose, and mannitol can effectively promote anthocyanin accumulation in the spathe of Z. hybrida and improve color appearance. At 499 mmol/L, glucose and mannitol significantly promote the expression of anthocyanin synthesis-related genes, in which glucose may regulate the expression of ZhMYB, ZhCHS, and ZhCHI through the HXK pathway.
[Objective] This study aims to explore the regulation of exogenous nitric oxide (NO) on the growth and quality of Leonurus japonicus under drought stress, in order to provide theoretical basis for cultivation and quality improvement of L. japonicus under drought stress. [Methods] 100 μmol/L sodium nitroprusside (SNP, a NO donor) was used as pretreatment, and 10%, 20%, and 30% polyethylene glycol (PEG)-6000 was used to simulate different degrees of drought stress. The effect of exogenous NO on seed germination, seedling growth, and the content of medicinal components of L. japonicus seedlings under drought stress was analyzed. [Results] (1) Seed germination under 10% and 20% PEG treatment was improved by the regulation of amylase activity through exogenous NO. (2) Exogenous NO mitigated growth inhibition of L. japonicus seedlings under drought stress, which was likely attributable to the reduction in malondialdehyde and hydrogen peroxide levels, thereby decreasing oxidative damage. (3) Analysis of medicinal components showed that exogenous NO enhanced leonurine hydrochloride content, stachydrine hydrochloride content, and flavonoid biosynthesis in L. japonicus under drought stress. [Conclusion] Exogenous application of NO could alleviate seed germination and seedling growth of L. japonicus under mild and moderate drought stress, and promote the accumulation of medicinal components under stress.
[Objective] The effect of NtCET4 gene overexpression in regulating tobacco flowering time was analyzed by constructing NtCET4 overexpression plants, and the feasibility of increasing the number of effective leaves of tobacco to improve tobacco yield based on NtCET4 manipulation was discussed. [Methods] Overexpression vector of NtCET4 was constructed. Transgenic individuals were obtained through the Agrobacterium-mediated leaf disc transformation. The transgenic plants were identified by PCR and GUS staining. The overexpressed lines were selected from transgenic lines based on qRT-PCR. The overexpressed plants were transplanted into fields to observe flowering time and leaf numbers. qRTPCR was used to identify relative expressions of NtCET4 before and after flowering. [Results] During the seedling stage, four transgenic lines showed significant increase in NtCET4 expression. These four transgenic lines with NtCET4 overexpression showed delaying flowering (about 14 days). Longer period of vegetative bud activity resulted in more valid leaves in the transgenic plants. NtCET4 expression in transgenic plants was increased from seedling to mature, and higher expression was detected before flowering relative to after flowering. [Conclusion] Overexpression of NtCET4 promotes the vegetative bud activity, delays flowering, and increases the number of valid leaves in tobacco.
