Stresses induced by the deficiency or excess of trace mineral elements, such as manganese (Mn), represent a common limiting factor for the production of crops like Brassica napus. To identify key genes involved in Mn allocation in B. napus and elucidate the underlying mechanisms, a member of the metal tolerance protein (MTP) family obtained in the previous screening of cDNA library of B. napus under Mn stress was selected as the research subject. Based on the sequence information and phylogenetic analysis, it was named as BnMTP10. It belongs to the Mn-cation diffusion facilitator (CDF) subfamily. Expression of BnMTP10 in yeast significantly improved the tolerance of transformants to excessive Mn and iron (Fe) and reduced the accumulation of Mn and Fe. However, the yeast transformants exhibited no significant changes in tolerance to excess cadmium, boron, aluminum, zinc, or copper. The qRT-PCR results demonstrated that the flowers of B. napus had the highest expression of BnMTP10, followed by roots and leaves. Subcellular localization studies revealed that BnMTP10 was localized in the endoplasmic reticulum (ER). Compared with wild-type plants, transgenic Arabidopsis overexpressing BnMTP10 exhibited enhanced tolerance to excessive Mn stress but showed no significant difference under Fe stress. Correspondingly, under excessive Mn stress, the Mn content in the roots of transgenic Arabidopsis increased significantly. However, under excessive Fe stress, the Fe content in transgenic Arabidopsis did not alter significantly. According to the results, we hypothesize that BnMTP10 may alleviate excessive Mn stress in plants by mediating Mn transport to the ER. This study facilitated our understanding of efficient mineral nutrients, and provided theoretical foundations and gene resources for breeding B. napus.
Brassica napus/genetics* ; Manganese/metabolism* ; Plants, Genetically Modified/genetics* ; Plant Proteins/physiology* ; Arabidopsis/metabolism* ; Gene Expression Regulation, Plant ; Phylogeny ; Cation Transport Proteins/metabolism* ; Stress, Physiological

Improving the nitrogen use efficiency (NUE) of Brassica napus is of significant importance for achieving the national goal of zero growth in chemical fertilizer application and ensuring the green development of the rapeseed industry. This study aims to explore the effects of the nitrate transporter gene BnaNRT1.5s on the nitrogen transport and NUE of B. napus, providing excellent genetic resources for the development of nitrogen-efficient B. napus varieties. The spatiotemporal expression of BnaA05.NRT1.5 as a key nitrogen responsive gene was profiled by qRT-PCR at different growth stages and for different tissue samples of B. napus 'Westar'. Subcellular localization was employed to examine its expression pattern in the cells. Additionally, CRISPR/Cas9 was used to create BnaNRT1.5s knockout lines, which were subjected to hydroponic experiments under high nitrogen (12.0 mmol/L) and low nitrogen (0.3 mmol/L) conditions. After the seedlings were cultivated for 21 days, root and shoot samples were collected for weighing, nitrogen content determination, xylem sap nitrate content assessment, and calculation of total nitrogen and NUE. The B. napus nitrate transporter BnaA05.NRT1.5 was localized to the cell membrane. During the seedling and early bolting stages, BnaA05.NRT1.5 was predominantly expressed in roots, while it was highly expressed in old leaves and mature silique skin during the reproductive stage. Compared with the wild type, the mutant BnaNRT1.5s showed significant increases in the dry weight and total nitrogen of seedlings under both high and low nitrogen conditions. Under low nitrogen conditions, NUE in the roots of BnaNRT1.5s significantly improved. Notably, under both high and low nitrogen conditions, the nitrate content in the shoots of BnaNRT1.5s decreased significantly, while that in the roots increased significantly, resulting in a significantly decreased shoot-to-root nitrate content ratio. BnaNRT1.5s is involved in regulating the transport of nitrate from the roots to the shoots, and its mutation enhances nitrogen absorption and utilization in B. napus seedlings, promoting seedling growth. This study not only provides references for understanding the physiological and molecular mechanisms by which BnaNRT1.5s regulates NUE but also offers valuable genetic resources for improving NUE in B. napus.
Brassica napus/genetics* ; Anion Transport Proteins/metabolism* ; Nitrogen/metabolism* ; Nitrate Transporters ; Plant Proteins/metabolism* ; Nitrates/metabolism* ; Gene Expression Regulation, Plant ; Biological Transport

The well-known detrimental effects of cadmium (Cd) on plants are chloroplast destruction, photosynthetic pigment inhibition, imbalance of essential plant nutrients, and membrane damage. Jasmonic acid (JA) is an alleviator against different stresses such as salinity and drought. However, the functional attributes of JA in plants such as the interactive effects of JA application and Cd on rapeseed in response to heavy metal stress remain unclear. JA at 50 µmol/L was observed in literature to have senescence effects in plants. In the present study, 25 µmol/L JA is observed to be a "stress ameliorating molecule" by improving the tolerance of rapeseed plants to Cd toxicity. JA reduces the Cd uptake in the leaves, thereby reducing membrane damage and malondialdehyde content and increasing the essential nutrient uptake. Furthermore, JA shields the chloroplast against the damaging effects of Cd, thereby increasing gas exchange and photosynthetic pigments. Moreover, JA modulates the antioxidant enzyme activity to strengthen the internal defense system. Our results demonstrate the function of JA in alleviating Cd toxicity and its underlying mechanism. Moreover, JA attenuates the damage of Cd to plants. This study enriches our knowledge regarding the use of and protection provided by JA in Cd stress.
Brassica napus/metabolism* ; Cadmium/toxicity* ; Catalase/metabolism* ; Cyclopentanes/pharmacology* ; Oxylipins/pharmacology* ; Photosynthesis ; Plant Leaves/metabolism* ; Superoxide Dismutase/metabolism*

Recently, more research about the plant bioreactor expressing genes encoding human proteins was reported. In the present study, the cDNA of the human gene keratinocyte growth factor 2 (KGF2) was replaced with plant preferred codons by PCR, and the modified full-length cDNA was cloned into the plant expression vector pCAMBIA-YO containing the oil-body promoter. The fusion construct pCAMBIA-YO-KGF2 was transformed into Brassica napus by Agrobacterium tumefacien-mediated cotyledon transformation method. The transgenic seedlings were identified by PCR, Southern and western blot analysis all showed that KGF2 gene was successfully expressed in in transgenic Brassica napus.
Brassica napus ; genetics ; metabolism ; Cloning, Molecular ; DNA, Complementary ; genetics ; Fibroblast Growth Factor 7 ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Humans ; Plants, Genetically Modified ; genetics ; Rhizobium ; genetics ; Transformation, Genetic