= Lateral root cap
The <lateral root cap> is the peripheral part of the <root cap>, lying around its central <columella (root cap)> and adjacent to outer <root (botany)> tissues. It is a tip-associated tissue, not a <lateral root>, which is an entire branch growing from another <root (botany)>.
Its position makes a transport route possible. In the 2005 <Arabidopsis thaliana> study, tissue-targeted expression of <AUX1> showed that <gravitropism> required <auxin> transport through the <lateral root cap> toward elongating <plant epidermis> <cells>. Disrupting <auxin> response in the receiving expanding epidermal population separately impaired the bend.<Root gravitropism requires lateral root cap and epidermal cells for transport and response to a mobile auxin signal by Ranjan Swarup and others>[Abstract; Figures1,5–7]{ref}
Signal detection, transport and response need not occur in the same <cell>. A useful diagram therefore traces a route from the gravity-sensitive cap region through the <lateral root cap> to the <root elongation zone>. An experiment removing <cells> from one region and an experiment blocking a specific transporter there ask different questions; their outcomes should not be collapsed into one claim that the region has only one function.
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