Ammonium-induced architectural and anatomical changes with altered suberin and lignin levels significantly change water and solute permeabilities of rice (Oryza sativa L.) roots
Ammonium-induced architectural and anatomical changes with altered suberin and lignin levels significantly change water and solute permeabilities of rice (Oryza sativa L.) roots
复制标题
DOI：
10.1007/s00425-015-2406-1
复制
发表时间：
2015-09
期刊：
影响因子：
4.3
通讯作者：
Kosala Ranathunge;L. Schreiber;Y. Bi;S. Rothstein
中科院分区：
文献类型：
--
作者：
Kosala Ranathunge;L. Schreiber;Y. Bi;S. Rothstein
主要结论非最佳铵水平显着改变根构型，解剖和根渗透性的水和营养离子。高铵态氮水平诱导了较强的质外体屏障，而低铵态氮水平则相反。然而，非最佳应用可能对植物生长和发育产生负面影响。在这项研究中，我们研究了不同水平的铵（NH 4+）[低（30或100 μ M）或最佳（300 μM）或高（1000或3000 μM）]如何影响1个月大的水培水稻根系的理化性质。不同NH 4+处理显著改变了根的构型和解剖结构。植物生长在低NH 4+有最长的根与弱沉积的木栓质和木质质外体屏障，它是相反的植物生长在高NH 4+。所选木栓质和木质素生物合成候选基因的相对表达水平，使用qRT-PCR测定，在低NH 4+的根中最低，而在高NH 4+的根中最高。这反映了木栓质和木质素含量，并显着降低根从低NH 4+导致更大的水力传导率（Lpr）和溶质渗透性（Psr）比根从最佳NH 4+。相反，在高NH 4+生长的根有显着更大的木栓质和木质素含量，这是反映了强大的障碍。这些障碍显着降低了根的Psrs，但未能降低根的Lpr低于那些生长在最佳NH 4+，这可以解释的物理性质的分子使用和孔的大小在质外体。结果表明，非最适NH 4+水平对水稻根系特性（包括LprandPsr）的影响不同，水稻根系能够成功地适应不断变化的根系环境。
Main conclusionNon-optimal ammonium levels significantly alter root architecture, anatomy and root permeabilities for water and nutrient ions. Higher ammonium levels induced strong apoplastic barriers whereas it was opposite for lower levels.Application of nitrogen fertilizer increases crop productivity. However, non-optimal applications can have negative effects on plant growth and development. In this study, we investigated how different levels of ammonium (NH4+) [low (30 or 100 μM) or optimum (300 μM) or high (1000 or 3000 μM)] affect physio-chemical properties of 1-month-old, hydroponically grown rice roots. Different NH4+treatments markedly altered the root architecture and anatomy. Plants grown in low NH4+had the longest roots with a weak deposition of suberised and lignified apoplastic barriers, and it was opposite for plants grown in high NH4+. The relative expression levels of selected suberin and lignin biosynthesis candidate genes, determined using qRT-PCR, were lowest in the roots from low NH4+, whereas, they were highest for those grown in high NH4+. This was reflected by the suberin and lignin contents, and was significantly lower in roots from low NH4+resulting in greater hydraulic conductivity (Lpr) and solute permeability (Psr) than roots from optimum NH4+. In contrast, roots grown at high NH4+had markedly greater suberin and lignin contents, which were reflected by strong barriers. These barriers significantly decreased thePsrof roots but failed to reduce theLprbelow those of roots grown in optimum NH4+, which can be explained in terms of the physical properties of the molecules used and the size of pores in the apoplast. It is concluded that, in rice, non-optimal NH4+levels differentially affected root properties includingLprandPsrto successfully adapt to the changing root environment.