Putative zeatin O‐glucosyltransferase OscZOG1 regulates root and shoot development and formation of agronomic traits in rice

Abstract

As a ubiquitous reaction, glucosylation controls the bioactivity of cytokinins in plant growth and development. Here we show that genetic manipulation of zeatin-O-glucosylation regulates the formation of important agronomic traits in rice by manipulating the expression of OscZOG1 gene, encoding a putative zeatin O-glucosyltransferase. We found that OscZOG1 was preferentially expressed in shoot and root meristematic tissues and nascent organs. The growth of lateral roots was stimulated in the overexpression lines, but inhibited in RNA interference lines. In shoots, knockdown of OscZOG1 expression by RNA interference significantly improved tillering, panicle branching, grain number per panicle and seed size, which are important agronomic traits for grain yield. In contrast, constitutive expression of OscZOG1 leads to negative effects on the formation of the grain-yielding traits with a marked increase in the accumulation levels of cis-zeatin O-glucoside (cZOG) in the transgenic rice plants. In this study, our findings demonstrate the feasibility of improving the critical yield-determinant agronomic traits, including tiller number, panicle branches, total grain number per panicle and grain weight by downregulating the expression level of OscZOG1. Our results suggest that modulating the levels of cytokinin glucosylation can function as a fine-tuning switch in regulating the formation of agronomic traits in rice.

Transcriptome Profiles Reveal the Growth-Promoting Mechanisms of Paenibacillus polymyxa YC0136 on Tobacco (Nicotiana tabacum L.)

“…Strain YC0136 attenuated the ability of zeatin conversion in tobacco by inhibiting the expression of cis-zeatin O-glucosyltransferase. This reduced the degradation of zeatin, allowing zeatin to play a role as a cytokinin (Kudo et al, 2012;Shang et al, 2016).…”

OsCYP71D8L as a key regulator involved in growth and stress response by mediating gibberellins and cytokinins homeostasis in rice

“…For examples, exogenous CK could increase rice yield potential by enhancing grain filling and bearing large panicles (Panda et al, 2018). Downregulation of OsCKX2 and OscZOG1 resulted in elevated CKs, and thereby improved yield-related traits including tiller numbers, panicle branches, and grain number per panicle in rice (Ashikari et al, 2005; Shang et al, 2016). Similarly, GA20ox1 affected grain number and yield by rebalancing activities of CKs and GAs in rice (Wu et al, 2016).…”

iTRAQ-Based Comparative Proteomic Analysis Provides Insights into Molecular Mechanisms of Salt Tolerance in Sugar Beet (Beta vulgaris L.)

“…In the present study, zeatin O-glucosyltransferase (Unigene0016372), a protein related to zeatin biosynthesis, was obviously increased in sugar beet exposed to salt. It was observed that zeatin O-glucosyltransferase OsZOG1 regulates root and shoot development and formation of agronomic traits in rice [58]. Overexpression of a zeatin O-glucosyltransferase gene significantly enhanced the accumulation of both CK and auxin in roots and lower leaves of transgenic tobacco plants when subjected to water deficit [59].…”