Analysis of QTLs for Flag Leaf Shape and Its Response to Elevated CO_2 in Rice(Oryza sativa)

To understand the responses of flag leaf shape in rice to elevated CO2 environment and their genetic characteristics, quantitative trait loci （QTLs） for flag leaf shape in rice were mapped onto the molecular marker linkage map of chromosome segment substitution lines （CSSLs） derived from a cross between a japonica variety Asominori and an indica variety IR24 under free air carbon dioxide enrichment （FACE, 200 μmol/mol above current levels） and current CO2 concentration （Ambient, about 370 μmol/mol）. Three flag-leaf traits, flag-leaf length （LL）, width （LW） and the ratio of LL to LW （RLW）, were estimated for each CSSL and their parental varieties. The differences in LL, LW and RLW between parents and in LL and LW within IR24 between FACE and Ambient were significant at 1% level. The continuous distributions and transgressive segregations of LL, LW and RLW were also observed in CSSL population, showing that the three traits were quantitatively inherited under both FACE and Ambient. A total of 16 QTLs for the three traits were detected on chromosomes 1, 2, 3, 4, 6, 8 and 11 with LOD （Log10-1ikelihood ratio） scores ranging from 3.0 to 6.7. Among them, four QTLs （qLL-6＊, qLL-8＊ qLW-4＊ and qRLW-6＊） were commonly detected under both FACE and Ambient. Therefore, based on the different responses to elevated CO2 in comparison with current CO2 level, it can be suggested that the expressions of several QTLs associated with flag-leaf shape in rice could be induced by the high CO2 level.

Transcriptome response of wheat Norin 10 to long-term elevated CO_2 under high yield field condition

The increasing atmospheric carbon dioxide concentration, caused by fossil fuel combustion and deforestation, plays an important role in plant growth and development. Wheat, as a major staple crop, adapts to climate change by tuning its inherent molecular mechanism, which is not well understood. The present study employed the RNA-Seq method to generate transcriptome profiles of the wheat Norin 10 in response to elevated CO_2 in comparison with ambient CO_2. The 10 895 787 high-quality clean reads of Norin 10 were assembled de novo using Trinity（without a reference genome） resulting in a total of 18 206 candidate transcripts with significant BLAST matches. GO enrichment analysis of Norin 10 at different CO_2 concentrations showed that some functional genes related to plastids, precursor metabolites, and energy, thylakoid and photosynthesis were apparently enriched at elevated CO_2（550 μmol mol^–1） in contrast to that at ambient CO_2（400 μmol mol^–1）; these findings were further confirmed by RT-PCR analysis. The findings demonstrated the specific effects of elevated CO_2 during long-term period in free air CO_2 enrichment（FACE） on transcriptome response of the high yielding wheat variety, Norin 10, which has a large spike.