Helical growth in plant organs: mechanisms and significance.
Many plants show some form of helical growth, such as the circular searching movements of growing stems and other organs (circumnutation), tendril coiling, leaf and bud reversal (resupination), petal arrangement (contortion) and leaf blade twisting. Recent genetic findings have revealed that such helical growth may be associated with helical arrays of cortical microtubules and of overlying cellulose microfibrils. An alternative mechanism of coiling that is based on differential contraction within a bilayer has also recently been identified and underlies at least some of these growth patterns. Here, I provide an overview of the genes and cellular processes that underlie helical patterning. I also discuss the diversity of helical growth patterns in plants, highlighting their potential adaptive significance and comparing them with helical growth patterns in animals.
School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia david.smyth@monash.edu.
David R
0000-0003-0455-9699
DR
Smyth
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D063245:Plant Development / Q000235:genetics / Q000502:physiology*
Cellulose microfibrils; Circumnutation; G-fibres; Handedness; Microtubules; Spiral; Tendrils