GhGASA10–1 promotes the cell elongation in fiber development through the phytohormones IAA-induced

Background Cotton is an important cash crop. The fiber length has always been a hot spot, but multi-factor control of fiber quality makes it complex to understand its genetic basis. Previous reports suggested that OsGASR9 promotes germination, width, and thickness by GAs in rice, while the overexpression of AtGASA10 leads to reduced silique length, which is likely to reduce cell wall expansion. Therefore, this study aimed to explore the function of GhGASA10 in cotton fibers development. Results To explore the molecular mechanisms underlying fiber elongation regulation concerning GhGASA10–1, we revealed an evolutionary basis, gene structure, and expression. Our results emphasized the conservative nature of GASA family with its origin in lower fern plants S. moellendorffii. GhGASA10–1 was localized in the cell membrane, which may synthesize and transport secreted proteins to the cell wall. Besides, GhGASA10–1 promoted seedling germination and root extension in transgenic Arabidopsis, indicating that GhGASA10–1 promotes cell elongation. Interestingly, GhGASA10–1 was upregulated by IAA at fiber elongation stages. Conclusion We propose that GhGASA10–1 may promote fiber elongation by regulating the synthesis of cellulose induced by IAA, to lay the foundation for future research on the regulation networks of GASA10–1 in cotton fiber development.

Design Considerations for Polyester Construction Stretch Removal and its Impact on Mooring System Design

Polyester based mooring systems offer unique challenges from design, analysis and installation perspective. Non-linear elongation behavior of the fiber is key to these challenges. A good understanding of the fiber elongation characteristics is critical to the design of a robust and efficient mooring system. Mooring systems are one of the primary contributors to the CAPEX of the Floating Production Units (FPU) and the drive to develop cost effective systems has led to improvements/changes to mooring systems. Off-vessel tensioning has been in use for several years, but the option has recently received more in-depth consideration. Off-vessel tensioning is becoming the standard for floating systems with the elimination of on-vessel tensioning systems. The elimination of on-vessel tensioning system brings upon new challenges in terms of mooring line installation and tensioning. A key driver for these systems is the polyester rope pre-load criteria primarily used to remove construction stretch and jump the creep curve that the system may experience. The challenges to each project are unique, however, understanding and assessing the key design impacts will be beneficial to the industry. This paper focuses on the design of a polyester based mooring system with focus on polyester fiber elongation characteristics and its impact on the design and installation. A polyester test program is established to understand the rope elongation behavior and impact of various pre-load levels. Installation assessment is also performed to understand the installation vessel requirements to achieve various pre-loads. Based on the studies, design updates are made to the mooring system and a novel two tension regime mooring system is proposed. Design impact of the two pre-tension system on various design criterions are evaluated and presented in this paper. The paper also makes recommendations on target pre-load and elongation to be considered in systems that do not plan to re-tension their system post installation. Authors appreciate that recommendations and observations reported may not be applicable for all types of floaters and mooring system.

Evolution of pectin synthesis relevant galacturonosyltransferase gene family and its expression during cotton fiber development

Background Pectin is a key substance involved in cell wall development, and the galacturonosyltransferases (GAUTs) gene family is a critical participant in the pectin synthesis pathway. Systematic and comprehensive research on GAUTs has not been performed in cotton. Analysis of the evolution and expression patterns of the GAUT gene family in different cotton species is needed to increase knowledge of the function of pectin in cotton fiber development. Results In this study, we have identified 131 GAUT genes in the genomes of four Gossypium species (G. raimondii, G. barbadense, G. hirsutum, and G. arboreum), and classified them as GAUT-A, GAUT-B and GAUT-C, which coding probable galacturonosyltransferases. Among them, the GAUT genes encode proteins GAUT1 to GAUT15. All GAUT proteins except for GAUT7 contain a conserved glycosyl transferase family 8 domain (H-DN-A-SVV-S-V-H-T-F). The conserved sequence of GAUT7 is PLN (phospholamban) 02769 domain. According to cis-elemet analysis, GAUT genes transcript levels may be regulated by hormones such as JA, GA, SA, ABA, Me-JA, and IAA. The evolution and transcription patterns of the GAUT gene family in different cotton species and the transcript levels in upland cotton lines with different fiber strength were analyzed. Peak transcript level of GhGAUT genes have been observed before 15 DPA. In the six materials with high fiber strength, the transcription of GhGAUT genes were concentrated from 10 to 15 DPA; while the highest transcript levels in low fiber strength materials were detected between 5 and 10 DPA. These results lays the foundation for future research on gene function during cotton fiber development. Conclusions The GAUT gene family may affect cotton fiber development, including fiber elongation and fiber thickening. In the low strength fiber lines, GAUTs mainly participate in fiber elongation, whereas their major effect on cotton with high strength fiber is related to both elongation and thickening.

A transversely hyperelastic constitutive model of flexible film composite

This paper presents a transversely hyperelastic constitutive model for predicting mechanical properties of flexible composites under unidirectional tension. A strain energy function which reflects the behavior of anisotropic elastic material is decomposed into three parts: matrix, fiber and fiber-matrix interaction. The fiber-matrix interaction was decomposed into in-plane shear stresses and out-of-plane shear stress, the in-plane shear stresses were related to the fiber elongation invariants, and the out-of-plane shear stress was related to the fiber elongation invariants and the matrix invariants. The fiber-matrix interaction considering shear factor was established. Based on fiber reinforced continuum mechanics, a transverse hyperelastic constitutive model including fiber, matrix and their interaction is developed. The transversely hyperelastic constitutive model is verified by the uniaxial tension tests. The constitutive model can be used to design the flexible structure of stratospheric airship.

GhGASA10-1 promotes the cell and fiber elongation through the phytohormones IAA-induced

Background: Cotton is an important cash crop. The fiber length has always been a hot spot, but multi-factor control of fiber quality makes it complex to understand its genetic basis. Previous reports suggested that OsGASR9 promotes germination, width, and thickness by GAs in rice, while the overexpression of AtGASA10 lead to a reduction in silique length, which is likely to reduce cell wall expansion. Therefore, this study aimed to explore function of GhGASA10 in cotton fibers development.Results: To explore the molecular mechanisms underlying fiber elongation regulation concerning GhGASA10-1, we revealed an evolutionary basis, gene structure, and expression. Our results emphasized the conservative nature of GASA family with its origin in lower fern plants S. moellendorffii. GhGASA10-1 was localized in the cell membrane, which may synthesize and transport secreted protein to the cell wall. Besides, GhGASA10-1 promoted seedling germination and root extension in transgenic Arabidopsis, indicating that GhGASA10-1 promotes cell elongation. Interestingly, GhGASA10-1 was upregulated by IAA at fiber elongation stages. Conclusion: We propose that GhGASA10-1 promotes fiber elongation by regulating the synthesis of cellulose induced by IAA, to lay the foundation for future research on the regulation network of GASA10-1 in cotton fiber development.