Beyond the sine law of plant gravitropism

摘要: The great German plant physiologist Wilhelm Pfeffer rightly claimed that “no is entirely without the power of movement” (1). If this fact remains underappreciated, it perhaps because movements typically unfold over minutes, hours, or days, and thus exceed attention span all but most dedicated observer. Among large array movements, tropisms—that is, those are directed toward away from an external stimulus such as gravity light—are fascinating they highlight beautifully sentient nature plants goal-directedness their growth habit. pervasiveness tropisms revealed when one stops to consider unlikeliness seeds lodged haphazardly within crevices a rugged terrain should sprout stems reliably find way up. Were not for ability young sense light gravity, forests would be impenetrable tangles branches growing in directions. Their prevalence kingdom explains why have been active area research since beginning 19th century. By end century, field had reached level development popularity eminent biologists, including Charles Darwin Pfeffer, could devote entire books topic (1, 2). Given long illustrious tradition research, might expect today’s biologists extracted useful information standard observational tropisms. A paper published PNAS convince readers much can still learned careful, quantitative observation biological processes. In systematic study shoot gravitropism 11 taxa, Bastien et al. (3) at once establish universal response process initial stem curving followed by apical straightening debunk idea current models offer plausible explanation process.