Light quality regulates plant biomass and fruit quality through a photoreceptor-dependent HY5-LHC/CYCB module in tomato

Increasing photosynthesis and light capture offers possibilities for improving crop yield and provides a sustainable way to meet the increasing global demand for food.However,the poor light transmittance of transparent plastic films and shade avoidance at high planting density seriously reduce photosynthesis and alter fruit quality in vegetable crops,and therefore it is important to investigate the mechanisms of light signaling regulation of photosynthesis and metabolism in tomato(Solanum lycopersicum).Here,a combination of red,blue,and white(R1W1B0.5)light promoted the accumulation of chlorophyll,carotenoid,and anthocyanin,and enhanced photosynthesis and electron transport rates by increasing the density of active reaction centers and the expression of the genes LIGHT-HARVESTING COMPLEX B(SlLHCB)and A(SlLHCA),resulting in increased plant biomass.In addition,R1W1B0.5 light induced carotenoid accumulation and fruit ripening by decreasing the expression of LYCOPENEβ-CYCLASE(SlCYCB).Disruption of SlCYCB largely induced fruit lycopene accumulation,and reduced chlorophyll content and photosynthesis in leaves under red,blue,and white light.Molecular studies showed that ELONGATED HYPOCOTYL 5(SlHY5)directly activated SlCYCB,SlLHCB,and SlLHCA expression to enhance chlorophyll accumulation and photosynthesis.Furthermore,R1W1B0.5 light-induced chlorophyll accumulation,photosynthesis,and SlHY5 expression were largely decreased in the slphyb1cry1 mutant.Collectively,R1W1B0.5 light noticeably promoted photosynthesis,biomass,and fruit quality through the photoreceptor(SlPHYB1 and SlCRY1)-SlHY5-SlLHCA/B/SlCYCB module in tomato.Thus,the manipulation of light environments in protected agriculture is a crucial tool to regulate the two vital agronomic traits related to crop production efficiency and fruit nutritional quality in tomato.

红光和远红光在调控植物生长发育及应答非生物胁迫中的作用

光作为重要的环境因子之一,不仅为植物光合作用提供能量,而且作为信号影响植物对外界环境的响应。该文综述了红光和远红光对植物生长发育和非生物胁迫响应的调控作用,重点阐述了光敏色素及下游光信号转录因子整合激素等内源信号调控植物种子萌发、下胚轴伸长、芽发育及开花的分子机制,以及红光和远红光在植物响应盐、干旱及温度胁迫中的作用机制。在挖掘植物感知和响应光环境机理的基础上,利用LED光谱技术对作物进行精确补光,有望提高作物产量、品质和抗逆性,同时推进实现“双碳”目标,减少能源消耗和环境污染。

High-performance porous carbon foams via catalytic pyrolysis of modified isocyanate-based polyimide foams for electromagnetic shielding

Porous carbon skeletons(PCSs)derived from isocyanate-based aromatic polyimide foams(PIFs)by high-temperature pyrolysis are very promising in the fabrication of high-performance polymer composite foams for electromagnetic interference(EMI)shielding due to their efficient conductive networks and facile preparation process.However,severe volumetric shrinkage and low graphitization degree is not conducive to enhancing the shielding efficiency of the PCSs.Herein,ferric acetylacetonate and carbon-nanotube coating have been introduced in isocyanate-based PIFs to greatly suppress the serious shrinkage during pyrolysis and improve the graphitization degree of the final carbon foams through the Fe-catalytic graphitization process,thereby endowing them with better EMI-shielding performance even at lower pyrolysis temperature compared to the control samples.Moreover,compressible polydimethylsiloxane(PDMS)composite foams with the as-prepared carbon foams as prefabricated PCSs have also been fabricated,which could provide not only stable shielding effectiveness(SE)performance even after a thousand compressions,but also multiple functions of Joule heating,thermal insulation and infrared stealth.This study offers a feasible route to prepare high-performance PCSs in a more energy-efficient manner via PIF pyrolysis,which is very promising in the manufacture of multifunctional conductive polymer composite foams.

Biomass-based aligned carbon networks with double-layer construction for tunable electromagnetic shielding with ultra-low reflectivity

Nowadays,carbon frameworks derived from natural biomaterials have attracted extensive attention for electromagnetic interference(EMI)shielding due to their renewability and affordability.However,it is critical and challenging to achieve effective regulation of shielding effectiveness(SE)as well as weaken the strong EM reflection of highly conductive biomass-based carbon materials.Herein,commercial cotton pads with oriented structure were selected as carbonaceous precursor to fabricate aligned carbon networks by pyrolysis,and the EMI SE of the samples with increased temperature of 800-1000℃ can be accurately controlled in the effective range of~21.7-29.1,~27.7-37.1 and~32.7-43.3 d B with high reflection coefficient of>0.8 by changing the cross-angle between the electric-field direction of incident EM waves and the fiber-orientation direction due to the occurrence of opposite internal electric field.Moreover,the further construction of Salisbury absorber-liked double-layer structure could result in an ultralow reflection coefficient of only~0.06 but enhanced SE variation range up to~38.7-49.3 d B during the adjustment of cross-angle,possibly due to the destructive interference of EM waves in the double-layer carbon networks.This work would provide a simple and effective way for constructing high-performance biomass carbon materials with adjustable EMI shielding and ultra-low reflectivity.

PROTECTIVE ROLES OF D1 PROTEIN TURNOVER AND THE XANTHOPHYLL CYCLE IN TOMATO(SOLANUM LYCOPERSICUM)UNDER SUB-HIGH TEMPERATURE AND HIGH LIGHT STRESS

D1 protein turnover and the xanthophyll cycle(XC)are important photo-protective mechanisms in plants that operate under adverse conditions.Here,streptomycin sulfate(SM)and dithiothreitol(DTT)were used in tomato plants as inhibitors of D1 protein turnover and XC to elucidate their photoprotec-tive impacts under sub-high temperature and high light conditions(HH,35°C,1000 limol m 2.S1).SM and DTT treatments significantly reduced the net photosynthetic rate,apparent quantum efficiency,maximum photochemical efficiency,and potential activity of photosystem II,leading to photoinhibition and a decline in plant biomass under HH.The increase in reactive oxygen species levels resulted in thylakoid membrane lipid peroxidation.In addition,there were increased non-photochemical quenching and decreased chlorophyll pigments in SM and DTT application,causing an inhibition of D1 protein production at both transcriptional and translational levels.Overall,inhibition of D1 turnover caused greater photoinhibition than XC inhibition.Additionally,the recovery levels of most photosynthesis indicators in DTT-treated plants were higher than in SM-treated plants.These findings support the view that D1 turnover has a more important role than XC in photoprotection in tomato under HH conditions.