Nitrogen rhizodeposition from corn and soybean,and its contribution to the subsequent wheat crops

Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.However,quantitative assessments of differences in the N derived from rhizodeposition(NdfR)between legumes and gramineous crops are lacking,and comparative studies on their contributions to the subsequent cereals are scarce.In this study,we conducted a meta-analysis of NdfR from leguminous and gramineous crops based on 34 observations published worldwide.In addition,pot experiments were conducted to study the differences in the NdfR amounts,distributions and subsequent effects of two major wheat(Triticum aestivum L.)-preceding crops,corn(Zea mays L.)and soybean(Glycine max L.),by the cotton wick-labelling method in the main wheat-producing areas of China.The meta-analysis results showed that the NdfR of legumes was significantly greater by 138.93%compared to gramineous crops.In our pot experiment,the NdfR values from corn and soybean were 502.32 and 944.12 mg/pot,respectively,and soybean was also significantly higher than corn,accounting for 76.91 and 84.15%of the total belowground nitrogen of the plants,respectively.Moreover,in different soil particle sizes,NdfR was mainly enriched in the large macro-aggregates(>2 mm),followed by the small macro-aggregates(2–0.25 mm).The amount and proportion of NdfR in the macro-aggregates(>0.25 mm)of soybean were 3.48 and 1.66 times higher than those of corn,respectively,indicating the high utilization potential of soybean NdfR.Regarding the N accumulation of subsequent wheat,the contribution of soybean NdfR to wheat was approximately 3 times that of corn,accounting for 8.37 and 4.04%of the total N uptake of wheat,respectively.In conclusion,soybean NdfR is superior to corn in terms of the quantity and distribution ratio of soil macro-aggregates.In future field production,legume NdfR should be included in the nitrogen pool that can be absorbed and utilized by subsequent crops,and the role and potential of leguminous plants as nitrogen source providers in crop rotation systems should be fully utilized.

Full-Length Transcriptome Analysis of Cultivated and Wild Tetraploid Peanut

The high-quality genomes and large-scale full-length cDNA sequences of allotetraploid peanuts have been sequenced and released,which has accelerated the functional genomics and molecular breeding research of peanut.In order to understand the difference in the transcriptional levels of wild and cultivated peanuts.In this study,we integrated of second-and third-generation sequencing technologies to sequence full-length transcriptomes in peanut cv.Pingdu9616 and its putative ancestor Arachis monticola.The RNA extracted from six different tissues(i.e.,roots,stems,leaves,flowers,needles and pods)were sampled at 20 days after flowering.A total of 31,764 and 33,981 high-quality transcripts were obtained from Monticola and Pingdu9616,respectively.The number of alternative splicing,the unit point mutation of variable adenylation,the number of open reading frames and the two-site mutation were identified in Pingdu9616 more than in Monticola,but the three-site mutation in Pingdu9616 was lower than in Monticola.1,691 LncRNAs,and 4,000 bp of maximum length of LncRNA was identified in Monticola and Pingdu9616.Furthermore,comparative analysis between transcript data shown that 56 transcription factor families were involved in Monticola,and Pingdu9616 and the number of transcription factors in Pingdu9616 was higher than that in Monticola,the number of expressed genes estimated in flower,root,young pod and leaf organs was higher in Monticola than Pingdu9616.Over all,our study provided a valuable resource of large-scale full-length transcripts for further research of the molecular breeding and functional analysis of genes.