Effects Of TaTAP46 Gene On Thousand Kernel Weight And Kernel Size In Wheat

The high yield is always the main goal of wheat breeding in China due to the large population base and increasing continuously population.In wheat breeding,the current situation is that the potential of conventional breeding to improve wheat yield is gradually disappearing.The high yield gene discovery is one of the effective methods to further increase wheat yield in high yield breeding.TATAP46 gene is one of important regulatory genes of TOR to regulate PP2 A in the TOR signaling pathway and is one of the important genes that determine yield related traits too.In this study,we analyzed gene structure,gene evolution,and expression sites of TaTAP46.Then we detected that the course of young ear differentiation,vegetative and reproductive growth,grouting of wheat,and the traits of ear length,spikelet numbers,TKW,KL,KW,KT of wheat regulated by TaTAP46.Also TaTAP46 gene interference influence on wheat water and N fertilizer utilizing.Finally,the haplotype selection of TaTAP46 gene was scanned among China of 505,and worldwide of 677 wheat varieties.The main conclusions are as follows:1.It was positively regulated the grain size and thousand kernel weight(TKW)of wheat by TaTAP46 gene.TKW,KL,KW and KT of TaTAP46 overexpression lines(TaTAP46-5AOE)was increased by 1.23%,1.97%,7.23% and 5.00% respectively than that of wild type lines(WT-KN199).However,TKW,KL,KW and KT of WT-KN199 was increased by10.03%,7.27%,9.20% and 7.47% respectively than that of TaTAP46 interference lines(TaTAP46-5A-RNAi).Compared with WT-KN199,the decrease of TaTAP46-5A-RNAi was more significant.2.It was positively regulated wheat growth,young panicle development and grain filling by TaTAP46 gene.The development of TaTAP46-5A-OE was faster approximately half a period than that of WT-KN199,while which of TaTAP46-5A-RNAi was slower half a period than that of WT-KN199.The vegetative growth period of TaTAP46-5A-OE was 0.5 days shorter than that of WT-KN199,and the reproductive growth period was 1.3 days longer than that of WT-KN199.However,the vegetative growth period of TaTAP46-5A-RNAi was 2.2days longer that of WT-KN199,and the reproductive growth period was 1.1 days shorter than that of WT-KN199.From 10 to 40 days post anthesis(DPA),the average daily kernel filling of TaTAP46-5A-RNAi was 1.27-4.51 mg less than that of WT-KN199(except for DPA25,which was 0.69 mg less).However,the average daily grain filling of TaTAP46-5A-OE was only less than 0.5 mg more than that of WT-KN199.Compared with WT-KN199,the kernelfilling rate of the TaTAP46-5A-RNAi decreased more significantly.Ear length of TaTAP46-5A-OE decreased by 0.99 cm and spikelet numbers increased by 0.75 spikelet than WTKN199,while there was no significant difference between TaTAP46-5A-RNAi and WTKN199.3.TaTAP46 gene affects the absorption and utilization of water and nitrogen fertilizer in wheat,and then affects wheat grain yield.From N fertilizer deficiency treatment to normal N fertilizer treatment,the TKW and KL of TaTAP46-5A-RNAi lines were increased respectively by 5.77% and 0.31%,However,KW and KT were decreased 1.14% and 0.16%.While TKW,KL,KW and KT of WT-Field increased by 7.58%,4.57%,9.36% and 6.87%,respectively.From the treatment of water saving to the treatment of normal irrigation amount,TKW of TaTAP46-5A-RNAi was increased by3.92%,However,KL,KW and KT of TaTAP46-5A-RNAi were reduced by 1.23%,1.98% and 1.77%,respectively.While WT-Field was increased by13.98%,4.52%,9.81% and 6.98%,respectively.Compared with WT-Field,the tatap46 mutant sensitivity of wheat to water and N stress decreased significantly.4.The KASP molecular marker-1462A/C of TaTAP46-5A gene can be used to distinguish the germplasm resources of wheat with different TKW,KL,KW and KT.The marker can be divided different varieties of wheat into Hap1 and Hap2 haplotypes.In the winter wheat region,the TKW,KL,KW and KT of Hap1 were increased 18.80%,4.51%,3.95% and 4.42%than that of Hap2,respectively.In spring wheat region,the TKW,KL,KW and KT of Hap1 were increased 13.30%,6.52%,2.86% and 2.82% than that of Hap2,respectively.This is mainly due to the higher expression of TaTAP46 gene induced by low temperature.In the process of wheat breeding in China,the proportion of Hap1 increased and that of Hap2 decreased gradually.Because of its higher yield,Hap1 has been strongly selected in all main wheat regions in the world and is an excellent haplotype.TaTAP46 is a gene associated with wheat yield.5.The structure of TaTAP46 gene is conserved and the expression sites of it is extensive.Three homologous genes,TaTAP46-5A,TaTAP46-5B,and TaTAP46-5D,were cloned from wheat.The expression level of TaTAP46-5A was the highest,followed by TaTAP46-5D,and TaTAP46-5B was the lowest.TaTAP46 was expressed in all stages of growth and development in wheat,and the highest expression levels were found in shoot tips at seedling stage,and1 cm,3cm long young panicles of wheat.6.The other interacted genes,such as all kinds of domain genes that decided on growth,development and pore protein genes that determined the nutrients absorption and transshipment,and all sorts of genes of functional enzyme,The gene interactions between TaTAP46 and them influence the growth and development of wheat by influencing the nutrient transport and metabolism,energy conversion,photosynthetic synthesis,etc.Ultimately,It result in TaTAP46 gene affect the wheat TKW,KL,KW,KT.The experiments of yeast twohybrid and LUC(Firefly luciferase and Renilla luciferase reporter gene assay)showed obvious complementary action between TaTAP46 gene and TaTIP41 gene in wheat.TaTAP46 gene may affect energy metabolism,C/N metabolism,ribosomal phosphorylation,and translation etc.in the wheat.TaTAP46 gene is a positive regulation gene of wheat TKW and grain size,which regulates wheat growth,young ear development and grain filling.Compared with the wild type,the sensitivity of wheat TaTAP46 mutant to water and nitrogen stress decreased significantly.The molecular marker-1462A/C of TaTAP46-5A gene can divide wheat varieties into Hap1 and Hap2 haplotypes.Hap1 is an excellent haplotype,which has been strongly selected in wheat regions of China and the world,and can be used as a marker for breeding high-yield wheat varieties.TaTAP46 is a yield related gene in wheat,and its structure is very conserved in species evolution.It has been susceptible to low temperature induction;By interacting with TaTIP41 gene,it affects energy metabolism,C/N metabolism,ribosomal phosphorylation,and translation etc.in the wheat.From seedling stage to maturity,it regulates the growth and development of wheat by regulating development of stem tip,spikelet,and development of young ear of floret differentiation stage,and ultimately leads to changes in wheat yield.