School of Life Science, Shandong University, Jinan, Shandong, China.
Plant Biotechnol J. 2018 Jan;16(1):86-99. doi: 10.1111/pbi.12751. Epub 2017 Jun 23.
Maize is a globally important food, feed crop and raw material for the food and energy industry. Plant architecture optimization plays important roles in maize yield improvement. PIN-FORMED (PIN) proteins are important for regulating auxin spatiotemporal asymmetric distribution in multiple plant developmental processes. In this study, ZmPIN1a overexpression in maize increased the number of lateral roots and inhibited their elongation, forming a developed root system with longer seminal roots and denser lateral roots. ZmPIN1a overexpression reduced plant height, internode length and ear height. This modification of the maize phenotype increased the yield under high-density cultivation conditions, and the developed root system improved plant resistance to drought, lodging and a low-phosphate environment. IAA concentration, transport capacity determination and application of external IAA indicated that ZmPIN1a overexpression led to increased IAA transport from shoot to root. The increase in auxin in the root enabled the plant to allocate more carbohydrates to the roots, enhanced the growth of the root and improved plant resistance to environmental stress. These findings demonstrate that maize plant architecture can be improved by root breeding to create an ideal phenotype for further yield increases.
玉米是全球重要的粮食、饲料作物和食品及能源工业原料。植物结构优化在提高玉米产量方面起着重要作用。PIN 蛋白在调节生长素在多个植物发育过程中的时空不对称分布方面起着重要作用。在这项研究中，玉米中 ZmPIN1a 的过表达增加了侧根的数量并抑制了其伸长，形成了具有更长的初生根和更密集的侧根的发达根系。ZmPIN1a 的过表达降低了株高、节间长度和穗位高度。这种对玉米表型的修饰增加了高密度种植条件下的产量，发达的根系提高了植物对干旱、倒伏和低磷环境的抗性。IAA 浓度、运输能力测定和外源 IAA 的应用表明，ZmPIN1a 的过表达导致从茎到根的 IAA 运输增加。根中生长素的增加使植物能够将更多的碳水化合物分配到根部，增强了根部的生长，并提高了植物对环境胁迫的抗性。这些发现表明，通过根培育可以改善玉米的植物结构，为进一步提高产量创造理想的表型。
