Mechanical stress acclimation in plants: Linking hormones and somatic memory to thigmomorphogenesis.

A single event of mechanical stimulation is perceived by mechanoreceptors that transduce rapid transient signalling to regulate gene expression. Prolonged mechanical stress for days to weeks culminates in cellular changes that strengthen the plant architecture leading to thigmomorphogenesis. The convergence of multiple signalling pathways regulates mechanically induced tolerance to numerous biotic and abiotic stresses. Emerging evidence showed prolonged mechanical stimulation can modify the baseline level of gene expression in naive tissues, heighten gene expression, and prime disease resistance upon a subsequent pathogen encounter. The phenotypes of thigmomorphogenesis can persist throughout growth without continued stimulation, revealing somatic-stress memory. Epigenetic processes regulate TOUCH gene expression and could program transcriptional memory in differentiating cells to program thigmomorphogenesis. We discuss the early perception, gene regulatory and phytohormone pathways that facilitate thigmomorphogenesis and mechanical stress acclimation in Arabidopsis and other plant species. We provide insights regarding: (1) the regulatory mechanisms induced by single or prolonged events of mechanical stress, (2) how mechanical stress confers transcriptional memory to induce cross-acclimation to future stress, and (3) why thigmomorphogenesis might resemble an epigenetic phenomenon. Deeper knowledge of how prolonged mechanical stimulation programs somatic memory and primes defence acclimation could transform solutions to improve agricultural sustainability in stressful environments.

The influence of mixed thickeners on printing over lyocell knitted fabric.

A quest was carried out to print on light weight lyocell knitted fabric with two mono-functional reactive dyes using pure guar gum (GG) or substituted guar gum (SGG) in combination with sodium alginate (Al) at different ratios. For each dyestuff, the print paste was prepared using mixed thickeners, namely GG/Al or SGA/Al at five different ratios. All samples were compared with the recipe containing pure sodium alginate. The empirical data show that the rheological behaviorisms of print paste-like viscosity and its other physical characteristics, such as paste add-on percentage (%) and penetration percentage (%), were dependent on the percentage of GG or SGG present in the thickener combination prepared with sodium Alginate. The combination of thickeners of these types also creates an impact on the final excellence of printed fabric, such as the colour yield, sharpness, stiffness of the fabric and the fastness of the colour. However, a few qualities are also dye dependent. The SGG/A combination gives a superior result when combining all the data with GG/A. Alginate with the small addition of SGG viz. the 80/20 or 60/40 mixture shows an excellent result in terms of printing characteristics. The thickener had no influential effect on the colour fastness rating.