A Novel Rice Gene, NRR Responds to Macronutrient Deficiency and Regulates Root Growth

Abstract

To better understand the response of rice to nutrient stress, we have taken a systematic approach to identify rice genes that respond to deficiency of macronutrients and affect rice growth. We report here the expression and biological functions of a previously uncharacterized rice gene that we have named NRR (nutrition response and root growth). NRR is alternatively spliced, producing two 5'-coterminal transcripts, NRRa and NRRb, encoding two proteins of 308 and 223 aa, respectively. Compared to NRRb, NRRa possesses an additional CCT domain at the C-terminus. Expression of NRR in rice seedling roots was significantly influenced by deficiency of macronutrients. Knock-down of expression of NRRa or NRRb by RNA interference resulted in enhanced rice root growth. By contrast, overexpression of NRRa in rice exhibited significantly retarded root growth. These results revealed that both NRRa and NRRb played negative regulatory roles in rice root growth. Our findings suggest that NRRa and NRRb, acting as the key components, modulate the rice root architecture with the availability of macronutrients.

Molecular mechanisms underpinning phosphorus‐use efficiency in rice

“…Considering the ways and means to increase P remobilization from roots in rice, achieving a greater size of the root system might be an option, several genes associated with enhanced root growth of rice under P deficiency have been identified (Gamuyao et al, ; Yang et al, ; Y. M. Zhang et al, ). A quantitative trait locus for P‐deficiency tolerance, Pup1 , was identified in the Indica type traditional rice variety Kasalath (Wissuwa & Ae, ; Wissuwa, Yano, & Ae, ).…”

“…The responsible gene was designated as phosphorus‐starvation tolerance 1 ( PSTOL1 ), which acts as an early root growth enhancer thereby enabling plants to acquire more Pi from soil (Gamuyao et al, ). Considering the other genes that influence root growth of rice, both OsMYB4P encoding an R2R3‐type MYELOBLASTOSIS protein (Yang et al, ) and nutrition response and root growth (Y. M. Zhang et al, ) have been identified. Overexpression of OsMYB4P enhances primary root length of rice, irrespective of Pi supply (Yang et al, ), whereas knockdown lines of nutrition response and root growth enhance rice root growth under Pi‐deficient conditions (Y. M. Zhang et al, ).…”

“…Considering the other genes that influence root growth of rice, both OsMYB4P encoding an R2R3‐type MYELOBLASTOSIS protein (Yang et al, ) and nutrition response and root growth (Y. M. Zhang et al, ) have been identified. Overexpression of OsMYB4P enhances primary root length of rice, irrespective of Pi supply (Yang et al, ), whereas knockdown lines of nutrition response and root growth enhance rice root growth under Pi‐deficient conditions (Y. M. Zhang et al, ). Making the best use of these identified genes is necessary, and integration of enhanced root growth with efficient root P remobilization would be a key aspect to consider when breeding rice genotypes for P‐deficient environments.…”

OsmiR530 acts downstream of OsPIL15 to regulate grain yield in rice

“…In order to generate the 35S::OsPL3-GFP plasmid, the full-length OsPL3 coding sequence without the stop codon was inserted into the Cam35S-GFP vector between the BamHI and XbaI sites. Rice protoplasts were transformed with the 35S::OsPL3-GFP construct as described previously (Zhang et al, 2012). GFP signals were observed with the FV10-ASW confocal microscope (Olympus).…”

Altered expression of CmNRRa changes flowering time of Chrysanthemum morifolium

“…We previously identified an NRR gene (nutrition response and root growth) in rice involved in root growth regulation in response to nitrogen and phosphorous nutrient deficiency (Zhang et al ., ). We also found that overexpression of NRRa in rice led to significantly delayed heading (Y. Zhang, G. Zhang, N. Xiao, L. Wang, Y. Fu, Z.…”