BnaA02.NIP6;1a encodes a boron transporter required for plant development under boron deficiency in Brassica napus

Exploring silique number in Brassica napus L.: Genetic and molecular advances for improving yield

Silique number is a crucial yield-related trait for the genetic enhancement of rapeseed (Brassica napus L.). The intricate molecular process governing the regulation of silique number involves various factors. Despite advancements in understanding the mechanisms regulating silique number in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), the molecular processes involved in controlling silique number in rapeseed remain largely unexplored. In this review, we identify candidate genes and review the roles of genes and environmental factors in regulating rapeseed silique number. We use genetic regulatory networks for silique number in Arabidopsis and grain number in rice to uncover possible regulatory pathways and molecular mechanisms involved in regulating genes associated with rapeseed silique number. A better understanding of the genetic network regulating silique number in rapeseed will provide a theoretical basis for the genetic improvement of this trait and genetic resources for the molecular breeding of high-yielding rapeseed.

Functional genomics of Brassica napus: Progresses, challenges, and perspectives

Brassica napus, commonly known as rapeseed or canola, is a major oil crop contributing over 13% to the stable supply of edible vegetable oil worldwide. Identification and understanding the gene functions in the B. napus genome is crucial for genomic breeding. A group of genes controlling agronomic traits have been successfully cloned through functional genomics studies in B. napus. In this review, we present an overview of the progress made in the functional genomics of B. napus, including the availability of germplasm resources, omics databases and cloned functional genes. Based on the current progress, we also highlight the main challenges and perspectives in this field. The advances in the functional genomics of B. napus contribute to a better understanding of the genetic basis underlying the complex agronomic traits in B. napus and will expedite the breeding of high quality, high resistance and high yield in B. napus varieties.

Physiological and transcriptomic analyses reveal that phytohormone pathways and glutathione metabolism are involved in the arsenite toxicity response in tomatoes

The main forms of inorganic arsenic (As) in soil are arsenate [As(V)] and arsenite [As(III)]. Both forms inhibit plant growth. Here, we investigate the effects of As(III) toxicity on the growth of tomatoes by integrating physiological and transcriptomic analyses. As(III) toxicity induces oxidative damage, inhibits photosynthetic efficiency, and reduces soluble sugar levels. As(III) toxicity leads to reductions in auxin, cytokinin and jasmonic acid contents by 29 %, 39 % and 55 %, respectively, but leads to increases in the ethylene precursor 1-amino-cyclopropane carboxylic acid, abscisic acid and salicylic acid contents in roots, by 116 %, 79 % and 39 %, respectively, thereby altering phytohormone signalling pathways. The total glutathione, reduced glutathione (GSH) and oxidized glutathione (GSSG) contents are reduced by 59 %, 49 % and 94 % in roots; moreover, a high GSH/GSSG ratio is maintained through increased glutathione reductase activity (increased by 214 %) and decreased glutathione peroxidase activity (decreased by 40 %) in the roots of As(III)-treated tomato seedlings. In addition, As(III) toxicity affects the expression of genes related to the endoplasmic reticulum stress response. The altered expression of aquaporins and ABCC transporters changes the level of As(III) accumulation in plants. A set of hub genes involved in modulating As(III) toxicity responses in tomatoes was identified via a weighted gene coexpression network analysis. Taken together, these results elucidate the physiological and molecular regulatory mechanism underlying As(III) toxicity and provide a theoretical basis for selecting and breeding tomato varieties with low As(III) accumulation. Therefore, these findings are expected to be helpful in improving food safety and to developing sustainable agricultural.

A critical review of plant adaptation to environmental boron stress: Uptake, utilization, and interplay with other abiotic and biotic factors

Boron (B) is an indispensable mineral nutrient for plants and is primarily taken up by roots mainly in the form of boric acid (H3BO3). Recently, research shows that B has a significant impact on plant growth and productivity due to its narrow range between deficiency and toxicity. Fertilization and other procedures to address B stress (deficiency and toxicity) in soils are generally expensive and time-consuming. Over the past 20 years, substantial studies have been conducted to investigate the mechanisms underlying B acquisition and the molecular regulation of B stress in plants. In this review, we discuss the effects of B stress on plant growth, physiology, and biochemistry, and finding on enhancing plant tolerance from the perspective of plant B uptake, transport, and utilization. We also refer to recent results demonstrating the interactions among B and other biological and abiotic factors, including nitrogen, phosphorus, aluminum, and microorganisms. Finally, emerging trends in this field are discussed.

Genome-wide identification of Brassicaceae histone modification genes and their responses to abiotic stresses in allotetraploid rapeseed

BACKGROUND

Histone modification is an important epigenetic regulatory mechanism and essential for stress adaptation in plants. However, systematic analysis of histone modification genes (HMs) in Brassicaceae species is lacking, and their roles in response to abiotic stress have not yet been identified.

RESULTS

In this study, we identified 102 AtHMs, 280 BnaHMs, 251 BcHMs, 251 BjHMs, 144 BnHMs, 155 BoHMs, 137 BrHMs, 122 CrHMs, and 356 CsHMs in nine Brassicaceae species, respectively. Their chromosomal locations, protein/gene structures, phylogenetic trees, and syntenies were determined. Specific domains were identified in several Brassicaceae HMs, indicating an association with diverse functions. Syntenic analysis showed that the expansion of Brassicaceae HMs may be due to segmental and whole-genome duplications. Nine key BnaHMs in allotetraploid rapeseed may be responsible for ammonium, salt, boron, cadmium, nitrate, and potassium stress based on co-expression network analysis. According to weighted gene co-expression network analysis (WGCNA), 12 BnaHMs were associated with stress adaptation. Among the above genes, BnaPRMT11 simultaneously responded to four different stresses based on differential expression analysis, while BnaSDG46, BnaHDT10, and BnaHDA1 participated in five stresses. BnaSDG46 was also involved in four different stresses based on WGCNA, while BnaSDG10 and BnaJMJ58 were differentially expressed in response to six different stresses. In summary, six candidate genes for stress resistance (BnaPRMT11, BnaSDG46, BnaSDG10, BnaJMJ58, BnaHDT10, and BnaHDA1) were identified.

CONCLUSIONS

Taken together, these findings help clarify the biological roles of Brassicaceae HMs. The identified candidate genes provide an important reference for the potential development of stress-tolerant oilseed plants.

Biogeochemical cycling, tolerance mechanism and phytoremediation strategies of boron in plants: A critical review

Boron (B) is an inimitable plant micronutrient, predominantly distinguished by super-narrow range between its deficiency and toxicity concentrations, which depends upon boron speciation in the growth media and form of living organisms. Moreover, the significant variations in its mobility amid different species, and distinctive inter and intra-species responses to extreme concentrations. Therefore, it is necessary to screen the bioavailability, speciation, biogeochemical cycling and exposure pathways of boron in the environment. The genes involved in the tolerance mechanism of boron in different plants were discussed in the current review paper. The functions related to scarcity and excess of boron concentration are assessed. The diverse plants implicated in phytoremediation of boron contaminated sites that restrict boron accumulation in food crops and health risks associated with soils containing deficit or surplus boron concentration were appraised. Ultimately, a summary of numerous strategies involved in the recovery and repair of boron-contaminated soils have been reviewed.

Transcriptome analysis reveals the molecular mechanism of boron deficiency tolerance in leaves of boron-efficient Beta vulgaris seedlings

Sugar beet (Beta vulgaris L.) has a high demand for B, and B deficiency inhibits normal growth and productivity. However, there is a lack of information on how B deficiency affects the growth of beet at the transcriptome level, and the factors that govern B utilisation efficiency. This study aimed to identify the genes differentially expressed under B deficiency and those that underlie the mechanisms of efficient B use in two sugar beet cultivars. Accordingly, B-efficient (H, KWS1197) and B-inefficient (L, KWS0143) sugar beet cultivars were used, and two levels of boron were employed in the hydroponic experiments: B0.1 (0.1 μM B, deficiency) and B50 (50 μM B, CK). The results showed that B deficiency inhibited leaf growth, significantly reduced B concentration and B transfer coefficient, and increased peroxidase (POD) activity and malondialdehyde and proline content. The transcriptome data showed that the B-efficient variety exhibited more differentially expressed genes than the B-inefficient variety. Metabolic pathways were the most critical pathways involved in the B deficiency response. The expression of POD, bHLH, WRKY transcription factors, and nodulin26-like intrinsic protein (NIP5;1) were upregulated in the KWS1197 variety. In conclusion, the KWS1197 variety had physiological advantages and a highly efficient B utilisation molecular mechanism, contributing to a high B deficiency tolerance. This study provides a theoretical basis for the adaptation mechanism to B deficiency in sugar beets.