Rice yield and heading date are two distinct traits controlled by quantitative trait loci (QTLs). The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice va...Rice yield and heading date are two distinct traits controlled by quantitative trait loci (QTLs). The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice varieties. Here, we report the cloning and characterization of Ghd8, a major QTL with pleiotropic effects on grain yield, heading date, and plant height. Two sets of near isogenic line populations were developed for the cloning of GhdS. Ghd8 was narrowed down to a 20-kb region containing two putative genes, of which one encodes the OsHAP3 subunit of a CCAAT-box binding protein (HAP complex); this gene was regarded as the Ghd8 candidate. A complementary test confirmed the identity and pleiotropic effects of the gene; interestingly, the genetic effect of Ghd8 was dependent on its genetic background. By regulating Ehdl, RFT1, and Hd3a, Ghd8 delayed flowering under long-day conditions, but promoted flowering under short-day conditions. Ghd8 up-regulated MOC1, a key gene controlling tillering and branching; this increased the number of tillers, primary and secondary branches, thus producing 50% more grains per plant. The ectopic expression of Ghd8 in Arabidopsis caused early flowering by 10 d-a situation similar to the one observed by its homolog AtHAP3b, when compared to wild-type under long-day conditions; these findings indicate the conserved function of Ghd8 and AtHAP3b in flowering in Arabidopsis. Our results demonstrated the important roles of Ghd8 in rice yield formation and flowering, as well as its opposite functions in flowering between rice and Arabidopsis under long-day conditions.展开更多
INTRODUCTIONThe transforming growth factor-β (TGF-β) superfamily com- prises TGF-βs, Activin, bone morphogenetic proteins (BMPs) and other related proteins. TGF-β superfamily members act through a heteromeric ...INTRODUCTIONThe transforming growth factor-β (TGF-β) superfamily com- prises TGF-βs, Activin, bone morphogenetic proteins (BMPs) and other related proteins. TGF-β superfamily members act through a heteromeric receptor complex,, comprised of type I and type II receptors at the cell surface that transduce intracellular signals via Smad complex or mitogen-activated protein kinase (MAPK) cascade.展开更多
We report new 40Ar/39Ar dating results ob-tained from total fusion and incremental-heating analyses of sanidine and biotite from three tuffs found interbedded within the fossil-bearing deposits of Liaoning, northeast ...We report new 40Ar/39Ar dating results ob-tained from total fusion and incremental-heating analyses of sanidine and biotite from three tuffs found interbedded within the fossil-bearing deposits of Liaoning, northeast China. The first is a new sample of the Bed 6 Sihetun tuff from the Yixian Formation, previously dated by our team as middle Early Cretaceous, and recently considered by Lo et al., partially reset due to metamorphism from a nearby ba-saltic sill. The second is the Yixian Bed 9 tuff from Heng-daozi considered by Lo et al. to be unaffected by metamor-phism and whose age, based on total fusion 40Ar/39Ar dating of biotite, argues for a Jurassic age for the Yixian Formation. The third tuff is a previously undated tuff from the upper part of the underlying Tuchengzi Formation. Single crystal total fusion 40Ar/39Ar analyses of the Sihetun sanidine showed homogeneous radiogenic Ar, Ca/K ratios, excellent reproducibility and gave a mean age of 125.0 ± 0.18 (1SD) ± 0.04 (SE) Ma. Single sanidine展开更多
文摘Rice yield and heading date are two distinct traits controlled by quantitative trait loci (QTLs). The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice varieties. Here, we report the cloning and characterization of Ghd8, a major QTL with pleiotropic effects on grain yield, heading date, and plant height. Two sets of near isogenic line populations were developed for the cloning of GhdS. Ghd8 was narrowed down to a 20-kb region containing two putative genes, of which one encodes the OsHAP3 subunit of a CCAAT-box binding protein (HAP complex); this gene was regarded as the Ghd8 candidate. A complementary test confirmed the identity and pleiotropic effects of the gene; interestingly, the genetic effect of Ghd8 was dependent on its genetic background. By regulating Ehdl, RFT1, and Hd3a, Ghd8 delayed flowering under long-day conditions, but promoted flowering under short-day conditions. Ghd8 up-regulated MOC1, a key gene controlling tillering and branching; this increased the number of tillers, primary and secondary branches, thus producing 50% more grains per plant. The ectopic expression of Ghd8 in Arabidopsis caused early flowering by 10 d-a situation similar to the one observed by its homolog AtHAP3b, when compared to wild-type under long-day conditions; these findings indicate the conserved function of Ghd8 and AtHAP3b in flowering in Arabidopsis. Our results demonstrated the important roles of Ghd8 in rice yield formation and flowering, as well as its opposite functions in flowering between rice and Arabidopsis under long-day conditions.
基金supported by grants by NIH grant AR-044741(Y-PL) and R01DE023813 (Y-PL)
文摘INTRODUCTIONThe transforming growth factor-β (TGF-β) superfamily com- prises TGF-βs, Activin, bone morphogenetic proteins (BMPs) and other related proteins. TGF-β superfamily members act through a heteromeric receptor complex,, comprised of type I and type II receptors at the cell surface that transduce intracellular signals via Smad complex or mitogen-activated protein kinase (MAPK) cascade.
基金This work was supported bythe Special Fund for the Major State Basic Research Projects of China (Grant No. G000077700) the Chinese Academy of Sciences (Grant No. KZCX3-J-03)+1 种基金 the National Natural Science Foundation of China (Grant No. 49832002) th
文摘We report new 40Ar/39Ar dating results ob-tained from total fusion and incremental-heating analyses of sanidine and biotite from three tuffs found interbedded within the fossil-bearing deposits of Liaoning, northeast China. The first is a new sample of the Bed 6 Sihetun tuff from the Yixian Formation, previously dated by our team as middle Early Cretaceous, and recently considered by Lo et al., partially reset due to metamorphism from a nearby ba-saltic sill. The second is the Yixian Bed 9 tuff from Heng-daozi considered by Lo et al. to be unaffected by metamor-phism and whose age, based on total fusion 40Ar/39Ar dating of biotite, argues for a Jurassic age for the Yixian Formation. The third tuff is a previously undated tuff from the upper part of the underlying Tuchengzi Formation. Single crystal total fusion 40Ar/39Ar analyses of the Sihetun sanidine showed homogeneous radiogenic Ar, Ca/K ratios, excellent reproducibility and gave a mean age of 125.0 ± 0.18 (1SD) ± 0.04 (SE) Ma. Single sanidine