Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
BMC Plant Biol. 2010 Aug 11;10:172. doi: 10.1186/1471-2229-10-172.
Mineral fertilization and pest control are essential and costly requirements for modern crop production. The two measures go hand in hand because plant mineral status affects plant susceptibility to pests and vice versa. Nutrient deficiency triggers specific responses in plants that optimize nutrient acquisition and reprogram metabolism. K-deficient plants illustrate these strategies by inducing high-affinity K-uptake and adjusting primary metabolism. Whether and how K deficient plants also alter their secondary metabolism for nutrient management and defense is not known.
Here we show that K-deficient plants contain higher levels of the phytohormone jasmonic acid (JA), hydroxy-12-oxo-octadecadienoic acids (HODs) and 12-oxo-phytodienoic acid (OPDA) than K-sufficient plants. Up-regulation of the 13-LOX pathway in response to low K was evident in increased transcript levels of several biosynthetic enzymes. Indole and aliphatic glucosinolates accumulated in response to K-deficiency in a manner that was respectively dependent or independent on signaling through Coronatine-Insensitive 1 (COI1). Transcript and glucosinolate profiles of K-deficient plants resembled those of herbivore attacked plants.
Based on our results we propose that under K-deficiency plants produce oxylipins and glucosinolates to enhance their defense potential against herbivorous insects and create reversible storage for excess S and N.
矿物质施肥和病虫害防治是现代作物生产的必要且昂贵的要求。这两项措施相辅相成，因为植物的矿物质状况会影响其对病虫害的易感性，反之亦然。养分缺乏会引发植物的特定反应，从而优化养分的获取并重新编程代谢。低钾植物通过诱导高亲和力钾吸收和调整初级代谢来举例说明这些策略。低钾植物是否以及如何改变其次生代谢以进行养分管理和防御尚不清楚。
在这里，我们表明，与钾充足的植物相比，低钾植物含有更高水平的植物激素茉莉酸（JA）、羟基-12-氧代-十八碳二烯酸（HODs）和 12-氧代-植二烯酸（OPDA）。低钾条件下 13-LOX 途径的上调在几种生物合成酶的转录水平增加中显而易见。吲哚和脂肪族硫代葡萄糖苷的积累是对低钾的响应，其方式分别依赖或不依赖于通过 Coronatine-Insensitive 1（COI1）的信号转导。低钾植物的转录物和硫代葡萄糖苷谱与受到草食性昆虫攻击的植物相似。
基于我们的结果，我们提出在低钾条件下，植物会产生氧化脂和硫代葡萄糖苷，以增强其对草食性昆虫的防御潜力，并为过量的 S 和 N 创造可逆转的储存。
