Plants dedicate a large amount of energy to the regulated production of living cells programmed to separate from roots into the external environment. This unusual process may be worth the cost because it enables the plant to dictate which species will share its ecological niche. For example, border cells can rapidly attract and stimulate growth in some microorganisms and repel and inhibit the growth of others. Such specificity may provide a way to control the dynamics of adjacent microbial populations in the soil to foster beneficial associations and inhibit pathogenic invasion. Plant genes controlling the delivery of border cells and the expression of their unique properties provide tools to genetically engineer plants with altered border cell quality and quantity. Such variants are being used to test the hypothesis that the function of border cells is to protect plant health by controlling the ecology of the root system.

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The use of herbal remedies is very popular in the United States, with >80 million people buying plant-derived preparations that are often highly degraded or potentially contaminated with nonefficacious plant material. A method utilizing DNA-based markers to identify highly fragmented or powdered plant material sold as botanicals in dietary supplements has been developed. By incorporating and streamlining a repair reaction that utilized fill-in and ligation reactions before the PCR steps, it was possible to amplify highly degraded or sheared DNA isolated from powdered plant material removed from over-the-counter capsules. The primers for the internal transcribed spacer (ITS) region of nuclear ribosomal DNA generate a PCR fragment compatible with the sizes of the repaired DNA. Moreover, a large data set in Genbank facilitated subsequent analysis. This method is a relatively rapid and simple system to facilitate the authentication, as well as the monitoring, of the purity of botanicals in dietary supplements, even those that are improperly dried or stored.