Genome-Wide Identification of the Brassinosteroid Signal Kinase Gene Family and Its Profiling under Salinity Stress.

Alfalfa (Medicago L.) is a high-quality perennial leguminous forage with the advantages of salt tolerance, mowing tolerance, high protein content, and other economically valuable characteristics. As the sixth class of plant hormones, brassinosteroids (BRs) play indispensable roles in modulating a variety of plant growth, maturation, and environmental adaptation processes, thereby influencing vegetal expansion and development. Brassinosteroid signal kinases (BSKs) are key cytoplasmic receptor kinases downstream of the BR signaling transduction pathway, participating in plant growth, development, and stress regulation. However, the phylogenetic and expression pattern analyses of the BSK gene family among the five alfalfa species have rarely been reported; in this study, 52 BSK family members were found in the genomes of the five subspecies, and phylogenetic trees were constructed according to protein sequences, allowing us to categorize all BSKs into seven distinct groups. Domain, conserved motif, and exon-intron structural analyses showed that most BSK members were relatively conserved, except for MtBSK3-2, MtBSK7-1, and MtBSK7-2, which may be truncated members. Intra-species collinearity and Ka/Ks analyses showed that purifying selection influenced BSK genes during evolution; most of the cis-acting elements in the promoter region were associated with responses, such as light, defense, and stress, anaerobic induction, MeJA, and abscisic acid. Expression pattern analysis indicated that the majority of alfalfa genes exhibited downregulation after reaching a peak at 0.5 h after treatment with 250 mM NaCl, especially for MsBSK14, MsBSK15, MsBSK17, MsBSK19, and MsBSK21; meanwhile, MsBSK4, MsBSK7, and MsBSK9 increased and were highly expressed at 12 h, demonstrating significantly altered expression patterns under salt stress; furthermore, MsBSK4, MsBSK7, and MsBSK9 exhibited expression specifically in the leaves. qRT-PCR analysis confirmed the expression trends for MsBSK4, MsBSK7, MsBSK9, MsBSK14, MsBSK15, and MsBSK16 matched the transcriptome data. However, the trends for MsBSK17, MsBSK19, and MsBSK21 diverged from the transcriptome data. Our study may provide a foundation for further functional analyses of BSK genes in growth, development, and salt stress tolerance in alfalfa.

Exploring the plasmodesmata callose-binding protein gene family in upland cotton: unraveling insights for enhancing fiber length.

Plasmodesmata are transmembrane channels embedded within the cell wall that can facilitate the intercellular communication in plants. Plasmodesmata callose-binding (PDCB) protein that associates with the plasmodesmata contributes to cell wall extension. Given that the elongation of cotton fiber cells correlates with the dynamics of the cell wall, this protein can be related to the cotton fiber elongation. This study sought to identify PDCB family members within the Gossypium. hirsutum genome and to elucidate their expression profiles. A total of 45 distinct family members were observed through the identification and screening processes. The analysis of their physicochemical properties revealed the similarity in the amino acid composition and molecular weight across most members. The phylogenetic analysis facilitated the construction of an evolutionary tree, categorizing these members into five groups mainly distributed on 20 chromosomes. The fine mapping results facilitated a tissue-specific examination of group V, revealing that the expression level of GhPDCB9 peaked five days after flowering. The VIGS experiments resulted in a marked decrease in the gene expression level and a significant reduction in the mature fiber length, averaging a shortening of 1.43-4.77 mm. The results indicated that GhPDCB9 played a pivotal role in the cotton fiber development and served as a candidate for enhancing cotton yield.

Function analysis of GhWRKY53 regulating cotton resistance to verticillium wilt by JA and SA signaling pathways.

WRKY transcription factors (TFs) play an important role in regulating the mechanism of plant self-defense. However, the function of most WRKY TFs in upland cotton (Gossypium hirsutum) is still unknown. Hence, studying the molecular mechanism of WRKY TFs in the resistance of cotton to Verticillium dahliae is of great significance to enhancing cotton disease resistance and improving its fiber quality. In this study, Bioinformatics has been used to characterize the cotton WRKY53 gene family. we analyzed the GhWRKY53 expression patterns in different resistant upland cotton cultivars treated with salicylic acid (SA) and methyl jasmonate (MeJA). Additionally, GhWRKY53 was silenced using a virus-induced gene silencing (VIGS) to determine the contribution of GhWRKY53 to V. dahliae resistance in cotton. The result showed that GhWRKY53 mediated SA and MeJA signal transduction pathways. After VIGS of the GhWRKY53, the ability of cotton to resist V. dahliae decreased, indicating that the GhWRKY53 could be involved in the disease resistance mechanism of cotton. Studies on the levels of SA and jasmonic acid (JA) and their related pathway genes demonstrated that the silencing of GhWRKY53 inhibited the SA pathway and activated the JA pathway, thereby reducing the resistance of plants to V. dahliae. In conclusion, GhWRKY53 could change the tolerance of upland cotton to V. dahliae by regulating the expression of SA and JA pathway-related genes. However, the interaction mechanism between JA and SA signaling pathways in cotton in response to V. dahliae requires further study.

An Adaptive and Robust Control Strategy for Real-Time Hybrid Simulation.

A real-time hybrid simulation (RTHS) is a promising technique to investigate a complicated or large-scale structure by dividing it into numerical and physical substructures and conducting cyber-physical tests on it. The control system design of an RTHS is a challenging topic due to the additional feedback between the physical and numerical substructures, and the complexity of the physical control plant. This paper proposes a novel RTHS control strategy by combining the theories of adaptive control and robust control, where a reformed plant which is highly simplified compared to the physical plant can be used to design the control system without compromising the control performance. The adaptation and robustness features of the control system are realized by the bounded-gain forgetting least-squares estimator and the sliding mode controller, respectively. The control strategy is validated by investigating an RTHS benchmark problem of a nonlinear three-story steel frame The proposed control strategy could simplify the control system design and does not require a precise physical plant; thus, it is an efficient and practical option for an RTHS.

GhFAD2-3 is required for anther development in Gossypium hirsutum.

BACKGROUND: In higher plants, the FAD2 gene encodes the microsomal oleate Δ12-desaturase, one of the key enzymes essential for the biosynthesis of the polyunsaturated lipids that serve many important functions in plant development and stress responses. FAD2 catalyzes the first step, in the biosynthesis of the polyunsaturated fatty acids (PUFAs) found in the cell membrane and cell wall, and it is thus of great importance to investigate the regulatory role of FAD2 in anther development. RESULTS: We reported the molecular characterization of the cotton (Gossypium hirsutum) GhFAD2 gene family and the essential role of GhFAD2-3 in cotton anther development. G. hirsutum contains four pairs of homoeologous FAD2 genes (GhFAD2-1 to GhFAD2-4). GhFAD2-3 is ubiquitously and relatively highly expressed in all analyzed tissues, particularly in anthers. Specific inhibition of GhFAD2-3 using the RNA interference approach resulted in male sterility due to impaired anther development at the stages from meiosis to maturation. The cellular phenotypic abnormality observed at the meiosis stage of the GhFAD2-3 silenced plant (fad2-3) coincides with the significant reduction of C18:2 in anthers at the same stage. Compared with that of the wild type (WT), the content of C18:1 was 41.48%, which increased by 5 fold in the fad2-3 anther at the pollen maturation stage. Moreover, the ratio of monounsaturated to polyunsaturated fatty acid was 5.43 in fad2-3 anther, which was much higher than that of the WT (only 0.39). Through compositional analysis of anthers cuticle and transcriptome data, we demonstrated it was unfavorable to the development of anther by regulating GhFAD2-3 expression level to increase the oleic acid content. CONCLUSIONS: Our work demonstrated the importance of C18:2 and/or C18:3 in the development of the pollen exine and anther cuticle in cotton and provided clue for further investigation of the physiological significance of the fatty acid composition for plant growth and development.