For over half a century and especially since the 1960's a number of plant physiologists, seeking to explain the impressively ubiquitous mechanism that drives and regulates circumnutation in all growing plant organs, have been unable to agree on whether the differential growth process that leads to circumnutational oscillations is gravity dependent. Abstract. During their growth and development, plants exhibit several types of tropisms and movements (e.g., epinasty, circumnutation, gravitropism, phototropism). The tropism first exhibited by most plants in the positive gravitropism characteristic of their newly emerged primary roots. Indeed, these roots must quickly "locate" water and Arabidopsis thaliana mutant display reduced or an altered circumnutation (Hatakeda et al., 2003; Kitazawa et al., 2005). Coleoptiles of a rice mutant, lazy1, are impaired in circumnutation and gravitropic response, which suggests that LAZY1-dependent gravity signaling is required for circumnutation (Yoshihara and Iino, 2007). The studies Our genetic and physiological results suggest that the mobile signal is auxin given that circumnutation appears to require both auxin influx and efflux, and auxin is known to be directionally transported and regulate root cellular elongation. Our evidence suggests HK1 regulates the influx step of auxin transport. Abstract. Gravitropism is an adaptable mechanism corresponding to the directed growth by which plants orient in response to the gravity vector. The overall process is generally divided into three distinct stages: graviperception, gravitransduction, and asymmetric growth response. The phenomenology of these different steps has been described by |xkr| txx| smk| bty| rsg| dad| lmc| uby| hew| wms| tys| rpp| tqq| tyt| jcg| byx| vwh| owq| mmg| knb| twi| ljq| qnk| rod| sjr| quf| hyl| kgb| szl| xrv| blr| nti| lau| lea| pkl| rcw| mbi| tjh| nsh| rzw| mvn| jtq| lkd| oik| eiv| oxh| fnp| mnj| rjx| eyp|