Targeted mutagenesis of BnTTG1 homologues generated yellow-seeded rapeseed with increased oil content and seed germination under abiotic stress.

Yellow seed is one desirable trait with great potential to improve seed oil quality and yield. The present study surveys the redundant role of BnTTG1 genes in the proanthocyanidins (PA) biosynthesis, oil content and abiotic stress resistance. Stable yellow seed mutants were generated after mutating BnTTG1 by CRISPR/Cas9 genome editing system. Yellow seed phenotype could be obtained only when both functional homologues of BnTTG1 were simultaneously knocked out. Homozygous mutants of BnTTG1 homologues showed decreased thickness and PA accumulation in seed coat. Transcriptome and qRT-PCR analysis indicated that BnTTG1 mutation inhibited the expression of genes involved in phenylpropanoid and flavonoid biosynthetic pathways. Increased seed oil content and alteration of fatty acid (FA) composition were observed in homozygous mutants of BnTTG1 with enriched expression of genes involved in FA biosynthesis pathway. In addition, target mutation of BnTTG1 accelerated seed germination rate under salt and cold stresses. Enhanced seed germination capacity in BnTTG1 mutants was correlated with the change of expression level of ABA responsive genes. Overall, this study elucidated the redundant role of BnTTG1 in regulating seed coat color and established an efficient approach for generating yellow-seeded oilseed rape genetic resources with increase oil content, modified FA composition and resistance to multiple abiotic stresses.

Establishment of new convenient two-line system for hybrid production by targeting mutation of OPR3 in allopolyploid Brassica napus.

The two-line pollination control system, which usually depends on the utilization of thermosensitive or photoperiod genic male-sterile lines, has been widely used in various crops. However, this system is susceptible to instability issues caused by uncontrollable weather fluctuations. A stable and handy two-line pollination control system is highly desirable in many crop species for heterosis exploitation. Oxophytodienoic acid reductase 3 (OPR3) was proven to be involved in jasmonate biosynthesis. In the present study, CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeat) was utilized to mutate two OPR3 homologs in Brassica napus. After two OPR3 homologs were simultaneously mutated, mutants exhibited complete male sterility, and fertility could be easily restored by exogenous MeJA treatment. Hybrids produced from crosses between the opr3 sterile lines and normal varieties exhibited heterosis. This new two-line system based on OPR3 mutation provides higher stability and convenience than traditional systems. By using exogenous MeJA treatment to restore fertility, the system enables more precise control of male fertility transition, which has great potential to significantly contribute to the maneuverable production of hybrid seeds in rapeseed as well as other Brassica species crops.

Optimizing Crystallization in Wide-Bandgap Mixed Halide Perovskites for High-Efficiency Solar Cells.

Wide-bandgap (WBG) perovskites have attracted considerable attention due to their adjustable bandgap properties, making them ideal candidates for top subcells in tandem solar cells (TSCs). However, WBG perovskites often face challenges such as inhomogeneous crystallization and severe nonradiative recombination loss, leading to high open-circuit voltage (VOC ) deficits and poor stability. To address these issues, a multifunctional phenylethylammonium acetate (PEAAc) additive that enhances uniform halide phase distribution and reduces defect density in perovskite films by regulating the mixed-halide crystallization rate, is introduced. This approach successfully develops efficient WBG perovskite solar cells (PSCs) with reduced VOC loss and enhanced stability. By applying this universal strategy to the FAMACsPb(I1- x Brx )3 system with a range of bandgaps of 1.73, 1.79, 1.85, and 1.92 eV, power conversion efficiencies (PCE) of 21.3%, 19.5%, 18.1%, and 16.2%, respectively, are attained. These results represent some of the highest PCEs reported for the corresponding bandgaps. Furthermore, integrating WBG perovskite with organic photovoltaics, an impressive PCE of over 24% for two-terminal perovskite/organic TSCs, with a record VOC of ≈ 2.2 V is achieved. This work establishes a foundation for addressing phase separation and inhomogeneous crystallization in Br-rich perovskite components, paving the way for the development of high-performance WBG PSCs and TSCs.

Remarkable Stability and Optoelectronic Properties of an All-Inorganic CsSn0.5Ge0.5I3 Perovskite Solar Cell.

Sn-Ge mixed perovskites have been proposed as promising lead-free candidates in the photovoltaics (PV) field. In this work, we discovered a stable P1 phase Sn-Ge mixed structure (CsSn0.5Ge0.5I3) with an appropriate band gap value of 1.19 eV, which manifests its unique structural stability and physics properties. The thermodynamic stability of this mixed structure under different growth conditions and all possible native defects are depicted in detail. The formation energies and dominant native point defects indicate that P1 phase CsSn0.5Ge0.5I3 exhibits unipolar self-doping behavior (p-type conductivity) and good defect tolerance while the growth condition changes. In addition, the calculation of light absorption confirmed that the P1 phase has a higher light absorption coefficient than that of MAPbI3 in the visible light range, showing excellent light absorption. Our work not only provides theoretical guidance for unraveling the unusual structural stability of Sn-Ge mixed perovskites, but also offers a useful scheme to modulate the stability and optoelectronic properties of Ge-based perovskites through alloy engineering.

Optoelectronic Properties of α-MoO3 Tuned by H Dopant in Different Concentration.

The optoelectronic properties of layered α-MoO3 are greatly limited due to its wide band gap and low carrier concentration. The insertion of hydrogen (H) can effectively tune the band structure and carrier concentration of MoO3. Herein, first-principles calculations were performed to unravel the physical mechanism of a H-doped α-MoO3 system. We found that the modulation of the electronic structure of H-doped MoO3 depends on the doping concentration and position of the H atoms. It was found that the band gap decreases at 8% doping concentration due to the strong coupling between Mo-4d and O-2p orbits when H atoms are inserted into the interlayer. More interestingly, the band gap decreases to an extreme due to the Mo-4d orbit when all the H atoms are inserted into the intralayer only, which has a remarkable effect on light absorption. Our research provides a comprehensive theoretical discussion on the mechanism of H-doped α-MoO3 from the doping positions and doping concentrations, and offers useful strategies on doping modulation of the photoelectric properties of layered transition metal oxides.

Security Risk Assessment Approach for Distribution Network Cyber Physical Systems Considering Cyber Attack Vulnerabilities.

With the increasing digitalization and informatization of distribution network systems, distribution networks have gradually developed into distribution network cyber physical systems (CPS) which are deeply integrated with traditional power systems and cyber systems. However, at the same time, the network risk problems that the cyber systems face have also increased. Considering the possible cyber attack vulnerabilities in the distribution network CPS, a dynamic Bayesian network approach is proposed in this paper to quantitatively assess the security risk of the distribution network CPS. First, the Bayesian network model is constructed based on the structure of the distribution network and common vulnerability scoring system (CVSS). Second, a combination of the fuzzy analytic hierarchy process (FAHP) and entropy weight method is used to correct the selectivity of the attacker to strike the target when cyber attack vulnerabilities occur, and then after considering the defense resources of the system, the risk probability of the target nodes is obtained. Finally, the node loads and node risk rates are used to quantitatively assess the risk values that are applied to determine the risk level of the distribution network CPS, so that defense strategies can be given in advance to counter the adverse effects of cyber attack vulnerabilities.

Integrated transcriptomic and metabolomic analyses revealed the molecular mechanism of terpenoid formation for salicylic acid resistance in Pulsatilla chinensis callus.

As a kind of traditional Chinese medicine, Pulsatilla chinensis (Bunge) Regel is well known for its anti-inflammation and anti-cancer activities, which are attributed to its active components including total saponins and monomers. To clarify the synthesis and metabolism mechanisms of class components in callus terpenes of P. chinensis, a certain concentration of salicylic acid (SA) hormone elicitor was added to the callus before being analysed by transcriptomic and metabolomic techniques. Results showed that the content of Pulsatilla saponin B4 in the callus suspension culture was significantly increased up to 1.99% with the addition of SA. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the differentially expressed genes were mainly enriched in 122 metabolic pathways, such as terpenoid metabolism-related pathways: terpenoid skeleton synthesis pathway, monoterpenoid biosynthesis pathways, diterpenoid biosynthesis pathways, and ubiquinone and other terpenoid-quinone biosynthesis pathways. A total of 31 differentially accumulated metabolites were obtained from four differential groups. Amongst 21 kinds of known chemical components in P. chinensis, deoxyloganic acid was the only monoterpenoid; the others are triterpenoids. In summary, this study found that SA elicitors can affect the metabolic changes of terpenoids in P. chinensis callus, which provided a basis for analysing the genetic regulation of terpenoid components of leucons.