Summary Identification of seed development regulatory genes is the key for the genetic improvement in rice grain quality. NF ‐Ys are the important transcription factors, but their roles in rice grain quality control and the underlying molecular mechanism remain largely unknown. Here, we report the functional characterization a rice NF ‐Y heterotrimer complex NF ‐ YB 1‐ YC 12‐ bHLH 144, which is formed by the binding of NF ‐ YB 1 to NF ‐ YC 12 and then bHLH 144 in a sequential order. Knock‐out of each of the complex genes resulted in alteration of grain qualities in all the mutants as well as reduced grain size in crnf‐yb1 and crnf‐yc12 . RNA ‐seq analysis identified 1496 genes that were commonly regulated by NF ‐ YB 1 and NF ‐ YC 12 , including the key granule‐bound starch synthase gene Wx . NF ‐ YC 12 and bHLH 144 maintain NF ‐ YB 1 stability from the degradation mediated by ubiquitin/26S proteasome, while NF ‐ YB 1 directly binds to the ‘G‐box’ domain of Wx promoter and activates Wx transcription, hence to regulate rice grain quality. Finally, we revealed a novel grain quality regulatory pathway controlled by NF ‐ YB 1‐ YC 12‐ bHLH 144 complex, which has great potential for rice genetic improvement.

Abscisic acid (ABA) and jasmonic acid (JA) both inhibit seed germination, but their interactions during this process remain elusive. Here, we report the identification of a 'SAPK10-bZIP72-AOC' pathway, through which ABA promotes JA biosynthesis to synergistically inhibit rice seed germination. Using biochemical interaction and phosphorylation assays, we show that SAPK10 exhibits autophosphorylation activity on the 177 th serine, which enables it to phosphorylate bZIP72 majorly on 71 st serine. The SAPK10-dependent phosphorylation enhances bZIP72 protein stability as well as the DNA-binding ability to the G-box cis-element of AOC promoter, thereby elevating the AOC transcription and the endogenous concentration of JA. Blocking of JA biosynthesis significantly alleviated the ABA sensitivity on seed germination, suggesting that ABA-imposed inhibition partially relied on the elevated concentration of JA. Our findings shed a novel insight into the molecular networks of ABA-JA synergistic interaction during rice seed germination.

We present one 3D cationic MOF (1-ClO(4)), which exhibits high thermal stability and strong alkali resistance. More importantly, it displays fast, selective capture of, and acts as a luminescent probe for, pollutant CrO(4)(2-) by anion exchange. Additionally, 1-ClO(4) exhibits interesting slow magnetic relaxation behavior at low temperature.

Rice (Oryza sativa L.) seed serves as a major food source for over half of the global population. Though it has been long recognized that phosphorylation plays an essential role in rice seed development, the phosphorylation events and dynamics in this process remain largely unknown so far. Here, we report the first large scale identification of rice seed phosphoproteins and phosphosites by using a quantitative phosphoproteomic approach. Thorough proteomic studies in pistils and seeds at 3, 7 days after pollination resulted in the successful identification of 3885, 4313 and 4135 phosphopeptides respectively. A total of 2487 proteins were differentially phosphorylated among the three stages, including Kip related protein 1, Rice basic leucine zipper factor 1, Rice prolamin box binding factor and numerous other master regulators of rice seed development. Moreover, differentially phosphorylated proteins may be extensively involved in the biosynthesis and signaling pathways of phytohormones such as auxin, gibberellin, abscisic acid and brassinosteroid. Our results strongly indicated that protein phosphorylation is a key mechanism regulating cell proliferation and enlargement, phytohormone biosynthesis and signaling, grain filling and grain quality during rice seed development. Overall, the current study enhanced our understanding of the rice phosphoproteome and shed novel insight into the regulatory mechanism of rice seed development.

BackgroundRice is a major crop worldwide. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) has become one of the most devastating diseases for rice. It has been clear that phosphorylation plays essential roles in plant disease resistance. However, the role of phosphorylation is poorly understood in rice-Xoo system. Here, we report the first study on large scale enrichment of phosphopeptides and identification of phosphosites in rice before and 24 h after Xoo infection.ResultsWe have successfully identified 2367 and 2223 phosphosites on 1334 and 1297 representative proteins in 0 h and 24 h after Xoo infection, respectively. A total of 762 differentially phosphorylated proteins, including transcription factors, kinases, epi-genetic controlling factors and many well-known disease resistant proteins, are identified after Xoo infection suggesting that they may be functionally relevant to Xoo resistance. In particular, we found that phosphorylation/dephosphorylation might be a key switch turning on/off many epi-genetic controlling factors, including HDT701, in response to Xoo infection, suggesting that phosphorylation switch overriding the epi-genetic regulation may be a very universal model in the plant disease resistance pathway.ConclusionsThe phosphosites identified in this study would be a big complementation to our current knowledge in the phosphorylation status and sites of rice proteins. This research represents a substantial advance in understanding the rice phosphoproteome as well as the mechanism of rice bacterial blight resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0541-2) contains supplementary material, which is available to authorized users.