| 1 | The strigolactone receptor D14 targets SMAX1 for degradation in response to GR24 treatment and osmotic stress显示文摘The effects of the phytohormone strigolactone(SL)and smoke-derived karrikins(KARs)on plants are generally distinct,despite the fact that they are perceived through very similar mechanisms.The homologous receptors DWARF14(D14)and KARRIKIN-INSENSITIVE2(KAI2),together with the F-box protein MORE AXILLARY GROWTH2(MAX2),mediate SL and KAR responses,respectively,by targeting different SMAX1-LIKE(SMXL)family proteins for degradation.These mechanisms are putatively well-insulated,with D14-MAX2 targeting SMXL6,SMXL7,and SMXL8 and KAI2-MAX2 targeting SMAX1 and SMXL2 in Arabidopsis thaliana.Recent evidence challenges this model.We investigated whether D14 can target SMAX1 and whether this occurs naturally.Genetic analysis indicates that the SL analog GR24 promotes D14-SMAX1 crosstalk.Although D14 shows weaker interactions with SMAX1 than with SMXL2 or SMXL7,D14 mediates GR24-induced degradation of SMAX1 in plants.Osmotic stress triggers SMAX1 degradation,which is protective,through SL biosynthesis and signaling genes.Thus,D14-SMAX1 crosstalk may be beneficial and not simply a vestige of the evolution of the SL pathway. | Qingtian Li Elena Sánchez Martín-Fontecha Aashima Khosla Alexandra R.F.White Sunhyun Chang Pilar Cubas David C.Nelson | 2022 | Plant Communications2022，3，2： | 5 |
| 2 | Influence of Ice on Soil Elemental Characterization via Portable X-Ray Fluorescence Spectrometry显示文摘Field portable X-ray fluorescence(PXRF)spectrometry has become an increasingly popular technique for in-situ elemental characterization of soils.The technique is fast,portable,and accurate,requiring minimal sample preparation and no consumables.However,soil moisture>20%has been known to cause fluorescence denudation and error in elemental reporting and few studies have evaluated the presence of soil moisture in solid form as ice.Gelisols(USDA Soil Taxonomy),permafrost-affected soils,cover a large amount of the land surface in the northern and southern hemispheres.Thus,the applicability of PXRF in those areas requires further investigation.PXRF was used to scan the elemental composition(Ba,Ca,Cr,Fe,K,Mn,Pb,Rb,Sr,Ti,Zn,and Zr)of 13 pedons in central and northern Alaska,USA.Four types of scans were completed:1)in-situ frozen soil,2)re-frozen soil in the laboratory,3)melted soil/water mixture in the laboratory,and 4)moisture-corrected soil.All were then compared to oven dry soil scans.Results showed that the majority of PXRF readings from in-situ,re-frozen,and melted samples were significantly underestimated,compared to the readings on oven dry samples,owing to the interference expected by moisture.However,when the moisture contents were divided into>40%and<40%groups,the PXRF readings under different scanning conditions performed better in the group with<40%moisture contents.Most elements of the scans on the melted samples with<40%moisture contents acceptably compared to those of the dry samples,with R^2 values ranging from 0.446(Mn)to 0.930(Sr).However,underestimation of the melted samples was still quite apparent.Moisture-corrected sample PXRF readings provided the best correlation to those of the dry,ground samples as indicated by higher R^2 values,lower root mean square errors(RMSEs),and slopes closer to 1 in linear regression equations.However,the in-situ(frozen)sample scans did not differ appreciably from the melted sample scans in their correlations to dry sample scans in terms of R^2 values(0.81 vs.0.88),RMSEs(1.06 vs.0.85),and slopes(0.88 vs.0.92).Notably,all of those relationships improved for the group with moisture contents<40%. | D.C.WEINDORF N.BAKR Y.ZHU A.MCWHIRT C.L.PING G.MICHAELSON C.NELSON K.SHOOK S.NUSS | 2014 | Pedosphere2014，24，1： | 3 |
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