SummaryDissecting the genetic basis of complex traits such as dynamic growth and yield potential is a major challenge in crops. Monitoring the growth throughout growing season in a large wheat population to uncover the temporal genetic controls for plant growth and yield‐related traits has so far not been explored. In this study, a diverse wheat panel composed of 288 lines was monitored by a non‐invasive and high‐throughput phenotyping platform to collect growth traits from seedling to grain filling stage and their relationship with yield‐related traits was further explored. Whole genome re‐sequencing of the panel provided 12.64 million markers for a high‐resolution genome‐wide association analysis using 190 image‐based traits and 17 agronomic traits. A total of 8327 marker‐trait associations were detected and clustered into 1605 quantitative trait loci (QTLs) including a number of known genes or QTLs. We identified 277 pleiotropic QTLs controlling multiple traits at different growth stages which revealed temporal dynamics of QTLs action on plant development and yield production in wheat. A candidate gene related to plant growth that was detected by image traits was further validated. Particularly, our study demonstrated that the yield‐related traits are largely predictable using models developed based on i‐traits and provide possibility for high‐throughput early selection, thus to accelerate breeding process. Our study explored the genetic architecture of growth and yield‐related traits by combining high‐throughput phenotyping and genotyping, which further unravelled the complex and stage‐specific contributions of genetic loci to optimize growth and yield in wheat.

Brassica napus L. has become one of the most important oil-bearing crops, and drought stress severely influences its yield and quality. By combining physio-biochemical characterization and transcriptome analysis, we studied the response of B. napus plants to different degrees of drought stress. Some physio-biochemical traits, such as fresh weight (FW), dry weight (DW), abscisic acid (ABA) content, net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr), were measured, and the total content of the epidermal wax/cutin, as well as their compositions, was determined. The results suggest that both stomatal transpiration and cuticular transpiration are affected when B. napus plants are subjected to varying degrees of drought stress. A total of 795 up-regulated genes and 1050 down-regulated genes were identified under severe drought stress by transcriptome analysis. Gene ontology (GO) enrichment analysis of differentially expressed genes (DEGs) revealed that the up-regulated genes were mainly enriched in the stress response processes, such as response to water deprivation and abscisic acid, while the down-regulated genes were mainly enriched in the chloroplast-related parts affecting photosynthesis. Moreover, overexpression of BnaA01.CIPK6, an up-regulated DEG, was found to confer drought tolerance in B. napus. Our study lays a foundation for a better understanding of the molecular mechanisms underlying drought tolerance in B. napus.

Epicuticular wax plays an important part in protecting plant aerial organs from biotic and abiotic stresses. Nitrogen is the key limiting nutrient for crops and influences metabolite synthesis. However, how nitrogen influences wax composition on rice leaf and sheath at different growth stages has not been systematically examined. In this study, a total of 19 wax compounds in rice leaf and sheath were detected by using gas chromatography−mass spectrometry. Permutational multivariate analysis of variance (PermANOVA) indicated a significant influence of both nitrogen and growth stage on rice leaf and sheath wax composition. Nitrogen influenced wax composition on leaf and sheath mainly at 70 and 110 d, while the growth stage significantly influenced wax composition under all nitrogen levels. Our study provides the first report that rice wax composition changes with nitrogen and growth stage. This may support exploring nitrogen application and the associated ecological effects.

Background: Plants respond to attackers by triggering phytohormones signaling associated metabolites, including herbivoreinduced plant volatiles (HIPVs). HIPVs can indirectly act against herbivory by recruitment of natural enemies and priming of neighboring plants. Ostrinia furnacalis and Mythimna separata are important insect herbivores of maize plants that have a devastating influence on yield. However, little is known about how maize temporally reconfigures its defense systems against these herbivores and variation of neighboring plant resistance.Results: This study investigated the effects of HIPVs on the behavior of the dominant predatory beetle Harmonia axyridis and priming in neighboring maize defense against O. furnacalis and M. separata over time. The results showed that maize damaged by either O. furnacalis or M. separata enhanced the release of volatiles including terpenes, aldehydes, alkanes and an ester, which elicited an increased attractive response to H. axyridis after 3 and 12 h, respectively. O. furnacalis damage resulted in accumulations of leaf jasmonic acid (JA) and salicylic acid in maize after 6 and 3 h, respectively, while M. separata damage only raised the JA level after 3 h. Furthermore, HIPVs were able to prime neighboring plants through the accumulation of JA after 24 h. Both larvae showed a significant decrease in weight accumulation after 48 h of feeding on the third leaves of the primed plant.Conclusion: Taken together, the findings provide a dynamic overview of how attacked maize reconfigures its volatiles and phytohormones to defend against herbivores, as well as priming of neighboring plants against oncoming attacks.