CSIRO Plant Industry, 306 Carmody Road, St Lucia QLD 4067, Australia.
BMC Plant Biol. 2014 Jan 13;14:22. doi: 10.1186/1471-2229-14-22.
Studies in Arabidopsis show that DELLA genes may differentially affect responses to biotrophic and necrophic pathogens. A recent report based on the study of DELLA-producing reduced height (Rht) genes in wheat and barley also hypothesized that DELLA genes likely increased susceptibility to necrotrophs but increased resistance to biotrophs.
Effects of uzu, a non-GA (gibberellic acid)-responsive semi-dwarfing gene, on Fusarium crown rot (FCR) resistance in barley were investigated. Fifteen pairs of near isogenic lines for this gene were generated and assessed under two different temperature regimes. Similar to its impacts on plant height, the semi-dwarfing gene uzu also showed larger effects on FCR severity in the high temperature regime when compared with that in the low temperature regime.
Results from this study add to the growing evidence showing that the effects of plant height on Fusarium resistances are unlikely related to DELLA genes but due to direct or indirect effects of height difference per se. The interaction between these two characteristics highlights the importance of understanding relationships between resistance and other traits of agronomic importance as the value of a resistance gene could be compromised if it dramatically affects plant development and morphology.
在拟南芥中的研究表明 DELLA 基因可能会对生物亲和性和坏死亲和性病原体的反应产生差异影响。最近的一份基于对小麦和大麦产生 DELLA 的矮化基因（Rht）的研究报告也假设，DELLA 基因可能会增加对坏死亲和性病原体的易感性，但会增加对生物亲和性病原体的抗性。
研究了 uzu （一种非 GA（赤霉素）反应性半矮化基因）对大麦镰刀菌冠腐病（FCR）抗性的影响。为此基因生成了 15 对近等基因系，并在两种不同的温度条件下进行了评估。与对株高的影响相似，uzu 半矮化基因在高温条件下对 FCR 严重程度的影响也大于在低温条件下的影响。
本研究的结果进一步证明，株高对镰刀菌抗性的影响可能与 DELLA 基因无关，而是由于株高差异本身的直接或间接影响。这两个特征之间的相互作用突出了理解抗性与其他具有农业重要性的性状之间关系的重要性，因为如果一个抗性基因对植物发育和形态有显著影响，那么它的价值可能会受到损害。
