In a world where there is growing pressure to grow more with a smaller environmental footprint, alternative forms of plant protection are needed. The root tips of most plants produce border cells in a mucilage that also contains extracellular DNA (exDNA), which is known to be involved in plant defence. A decade after we first demonstrated that there was varietal difference in the number of border cells in Australian cotton cultivars, we enumerated current commercial cultivars and assessed the level of exDNA produced by individual root tips. The results exposed that there has been a change in the number of border cells per root tip, that cultivar variation still exists and that the recovered levels of exDNA also differs. However, there was no correlation between border cell number and disease resistance to two of the major wilt pathogens and the levels of exDNA did not change when a root tip suspension was incubated with spores of fungal pathogens. The results imply that, while there is potential for border cells and root tip properties to be incorporated into breeding programmes, we still need to develop a better understanding of how root tips are able to influence disease epidemiology if we are to capitalise on this phenotypic property.

中文翻译：

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Bollgard3 棉花的边界细胞计数和细胞外 DNA 表达水平

在一个越来越大的压力以更小的环境足迹增长的世界中，需要替代形式的植物保护。大多数植物的根尖在粘液中产生边界细胞，该粘液还含有细胞外 DNA (exDNA)，已知其参与植物防御。在我们首次证明澳大利亚棉花品种的边界细胞数量存在品种差异十年后，我们列举了当前的商业品种并评估了单个根尖产生的 exDNA 水平。结果表明，每个根尖的边界细胞数量发生了变化，品种变异仍然存在，并且exDNA的恢复水平也不同。然而，边界细胞数量与对两种主要枯萎病病原体的抗病性之间没有相关性，并且当根尖悬浮液与真菌病原体的孢子一起孵育时，exDNA 的水平没有变化。结果意味着，虽然边界细胞和根尖特性有可能被纳入育种计划，但如果我们要利用这种表型特性，我们仍然需要更好地了解根尖如何影响疾病流行病学.