OsNOA1 functions in a threshold-dependent manner to regulate chloroplast proteins in rice at lower temperatures

Abstract

BackgroundAlthough decreased protein expressions have been observed in NOA1 (Nitric Oxide Associated protein 1) deficient plants, the molecular mechanisms of how NOA1 regulates protein metabolism remain poorly understood. In this study, we have used a global comparative proteomic approach for both OsNOA1 suppression and overexpression transgenic lines under two different temperatures, in combination with physiological and biochemical analyses to explore the regulatory mechanisms of OsNOA1 in rice.ResultsIn OsNOA1-silenced or highly overexpressed rice, considerably different expression patterns of both chlorophyll and Rubisco as well as distinct phenotypes were observed between the growth temperatures at 22 °C and 30 °C. These observations led us to hypothesize there appears a narrow abundance threshold for OsNOA1 to function properly at lower temperatures, while higher temperatures seem to partially compensate for the changes of OsNOA1 abundance. Quantitative proteomic analyses revealed higher temperatures could restore 90% of the suppressed proteins to normal levels, whereas almost all of the remaining suppressed proteins were chloroplast ribosomal proteins. Additionally, our data showed 90% of the suppressed proteins in both types of transgenic plants at lower temperatures were located in the chloroplast, suggesting a primary effect of OsNOA1 on chloroplast proteins. Transcript analyses, along with in vitro pull-down experiments further demonstrated OsNOA1 is associated with the function of chloroplast ribosomes.ConclusionsOur results suggest OsNOA1 functions in a threshold-dependent manner for regulation of chloroplast proteins at lower temperatures, which may be mediated by interactions between OsNOA1 and chloroplast ribosomes.Electronic supplementary materialThe online version of this article (10.1186/s12870-018-1258-9) contains supplementary material, which is available to authorized users.

Fine Mapping of the QTL cqSPDA2 for Chlorophyll Content in Brassica Napus L.

“…Qinghai Province is located in the Qinghai-Tibet Plateau. The average temperature during crop growth is lower, and the expression level of BnaA02g30310D (GCH-1) in NILs (aa) and ZS11 was more strongly expressed at three stages in the study, especially at the six-leaf stage, which is consistent with the results obtained by He [33,34].…”

“…Yang et al [33] found that the chlorophyll content decreased with increasing OsNOA1 at a low temperature (22 °C). He [34] suggested that OsNOA1 directly regulates the chloroplast self-coding protein by affecting the function of the chloroplast ribosome and then transmits the signal to the nucleus through the chloroplast retrograde signal pathway mediated by Mg protoporphyrin IX, further affecting the expression of chloroplast protein encoded by the nuclear gene. Qinghai Province is located in the Qinghai-Tibet Plateau.…”

Nitrate Reductase-Mediated Nitric Oxide Regulates the Leaf Shape in Arabidopsis by Mediating the Homeostasis of Reactive Oxygen Species

“…NO affects photosynthesis and photorespiration in various plants [53,54]. For example, OsNOA1 loss-of-function mutations in rice reduced chlorophyll levels during low temperature [55]. It was also reported that the application of a NO donor, SNP, could enhance the photosynthetic activity and reduce the Chl degradation [56].…”

Fine mapping of the QTL cqSPDA2 for chlorophyll content in Brassica napus L.

“…Yang et al [37] found that the chlorophyll content decreased with increasing OsNOA1 at a low temperature (22 °C). He [38] suggested that OsNOA1 directly regulates chloroplast-encoded proteins by affecting the function of the chloroplast ribosome and then transmits a signal to the nucleus through the chloroplast retrograde signaling pathway mediated by Mg protoporphyrin IX, further affecting the expression of chloroplast proteins encoded by the nuclear genes. The location of this study, Qinghai Province, is on the Qinghai-Tibet Plateau, where the average temperature during crop growth is low.…”