ABSTRACT

Height and leaf morphology are important agronomic traits of the major crop plant rice (Oryza sativa). In previous studies, the dwarf and narrow leaf genes (dnl1, dnl2 and dnl3) have identified in rice. Using the Ac/Ds knockout system, we found a new dwarf and narrow leaf (dnl) mutant and identified mutated gene. The dnl-4 mutant showed reduced plant height and leaf blade width compared to the wild type, and increased leaf inclination. The morphological defects of the mutant were caused by the suppressed expression of the DNL-4 gene, which encodes a pfkB carbohydrate kinase protein. These results suggest that DNL-4 expression is involved in modulating plant height and leaf growth. Furthermore, DNL-4 expression also affects productivity in rice: the dnl-4 mutant exhibited reduced panicle length and grain width compared with the wild type. To understand DNL-4 function in rice, we analyzed the expression levels of leaf growth-related genes, such as NAL1, NAL7, and CSLD4, in the dnl-4 mutant. Expression of NAL1 and NAL7 was downregulated in the dnl-4 mutant compared to the wild type. The observation that DNL-4 expression corresponded with that of NAL1 and NAL7 is consistent with the narrow leaf phenotype of the dnl-4 mutant. These results suggest that DNL-4 regulates plant height and leaf structure in rice.

摘要

高度和叶片形态是主要农作物水稻（Oryza sativa）的重要农艺性状。在以前的研究中，水稻中已经鉴定出矮叶和窄叶基因（dnl1，dnl2和dnl3）。使用Ac / Ds敲除系统，我们发现了一个新的矮窄叶（dnl）突变体，并鉴定了突变基因。该DNL-4突变体显示出降低的植物高度和相对于野生型叶片宽度和增加的叶倾斜度。突变体的形态缺陷是由DNL-4基因的抑制表达引起的，该基因编码pfkB碳水化合物激酶蛋白。这些结果表明DNL-4表达参与调节植物高度和叶片生长。此外，DNL-4的表达也影响水稻的生产力：与野生型相比，dnl-4突变体的穗长度和籽粒宽度降低。为了了解DNL-4在水稻中的功能，我们分析了dnl-4突变体中与叶片生长相关的基因（如NAL1，NAL7和CSLD4）的表达水平。与野生型相比，dnl-4突变体中NAL1和NAL7的表达下调。的观察结果DNL-4表达与对应的NAL1和NAL7与dnl-4突变体的窄叶表型一致。这些结果表明，DNL-4调节水稻的株高和叶片结构。