Breeding crops with resistance is an efficient way to control diseases. However, increased resistance often has a fitness penalty. Thus, simultaneously increasing disease resistance and yield potential is a challenge in crop breeding. In this study, we found that downregulation of microRNA-156 (miR-156) and overexpression of Ideal Plant Architecture1 (IPA1) and OsSPL7, two target genes of miR-156, enhanced disease resistance against bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo), but reduced rice yield. We discovered that gibberellin signalling might be partially responsible for the disease resistance and developmental defects in IPA1 overexpressors. We then generated transgenic rice plants expressing IPA1 with the pathogen-inducible promoter of OsHEN1; these plants had both enhanced disease resistance and enhanced yield-related traits. Thus, we have identified miR-156–IPA1 as a novel regulator of the crosstalk between growth and defence, and we have established a new strategy for obtaining both high disease resistance and high yield.
培育抗病作物是防治疾病的有效途徑。然而，抗性的增強(qiáng)往往會導(dǎo)致產(chǎn)量下降。因此，同時提高抗病性和產(chǎn)量潛力對于作物育種來說是一種挑戰(zhàn)。通過下調(diào)miR156和過表達(dá)miR156的兩個靶基因IPA1和OsSPL7，大幅增強(qiáng)了水稻對白葉枯病的抗性，但造成水稻產(chǎn)量下降。我們發(fā)現(xiàn)赤霉素信號可能部分地與IPA1過表達(dá)株系的抗病性和發(fā)育缺陷有關(guān)。然后，我們用OsHEN1的病菌誘導(dǎo)性啟動子產(chǎn)生表達(dá)IPA1的轉(zhuǎn)基因水稻植株，這些植株的抗病性增強(qiáng)，產(chǎn)量相關(guān)性狀增加。因此，我們將miR-156–IPA1確定為生長和防衛(wèi)之間的新調(diào)節(jié)因子，并建立了獲得高抗病性和高產(chǎn)量的新策略。