Over-expression of AtEXLA2 alters etiolated arabidopsis hypocotyl growth

• DOI: 10.1093/aob/mcu221
• Publication Date: 2014-12-10T06:48:39Z
• Authors: Agnieszka Karolin...; Bram Van Loock; Dmitry Suslov; Marios Nektarios ...; Jean-Pierre Verbelen; Kris Vissenberg
• Keywords: Xyloglucan; Expansin; Root hair; Lateral root

Background and Aims Plant stature shape are largely determined by cell elongation, a process that is strongly controlled at the level of wall. This associated with presence many wall proteins implicated in elongation process. Several enzyme families have been suggested to be involved weakening wall, these include xyloglucan endotransglucosylases/hydrolases (XTHs), yieldins, lipid transfer expansins. Although expansins subject much research, role involvement expansin-like genes/proteins remain mostly unclear. study investigates expression function AtEXLA2 (At4g38400), member A (EXLA) family arabidposis, considers its possible metabolism growth. Methods Transgenic plants Arabidopsis thaliana were grown, lines over-expressing identified. Plants grown dark, on media containing growth hormones or precursors, gravistimulated. Hypocotyls studied using transmission electron microscopy extensiometry. Histochemical GUS (β-glucuronidase) stainings performed. Key ResultsAtEXLA2 one three EXLA members arabidopsis. The protein lacks typical domain responsible for expansin activity, but contains presumed cellulose-interacting domain. Using promoter::GUS lines, was seen germinating seedlings, hypocotyls, lateral root cap cells, columella cells central cylinder basally zone root, during different stages development. Furthermore, promoter activity detected petioles, veins leaves filaments, also peduncle flowers just beneath papillae. Over-expression resulted an increase >10 % length dark-grown hypocotyls slightly thicker walls non-rapidly elongating etiolated hypocotyl cells. Biomechanical analysis creep tests showed over-expression may decrease strength arabidopsis hypocotyls. Conclusions It concluded as positive regulator interference cellulose metabolism, deposition organization.