Boller, T. | Search bioRxiv

bioRxiv2021

Transcriptomic profiling uncovers novel players in innate immunity in Arabidopsis thaliana

In this research a high-throughput RNA sequencing based transcriptome analysis technique (RNA-Seq) was used to evaluate differentially expressed genes (DEGs) in the wild type Arabidopsis seedling in response to flg22, a well-known microbe-associated molecular pattern (MAMP), and AtPep1, a well-known peptide representing an endogenous damage-associated molecular patterns (DAMP). The results of our study revealed that 1895 (1634 up-regulated and 261 down-regulated) and 2271 (1706 up-regulated and 565 down-regulated) significant differentially expressed genes in response to flg22 and AtPep1 treatment, respectively. Among significant DEGs, we observed that a number of hitherto overlooked genes have been found to be induced upon treatment with either flg22 or with AtPep1, indicating their possible involvement in innate immunity. Here, we characterized two of them, namely PP2-B13 and ACLP1. pp2-b13 and aclp1 mutants showed an increased susceptibility to infection by the virulent pathogen Pseudomomas syringae pv tomato mutant hrcC-, as evidenced by an increased growth of the pathogen in planta. Further we present evidence that the aclp1 mutant was deficient in ethylene production upon flg22 treatment, while the pp2-b13 mutant, was deficient in ROS production. The results from this research provide new information to a better understanding of the immune system in Arabidopsis.

plant biology↗

bioRxiv2020

Influence of spatial arrangement, biofertilizers and bioirrigation on the performance of legume-millet intercropping system in rainfed areas of southern India

Biofertilization via the inoculation with arbuscular mycorrhizal fungi (AMF), combined with rhizobia and plant growth promoting rhizobacteria (PGPR), are beginning to become established as an effective and sustainable measure to improve yields. Biofertilization might have a particular potential to boost the yield of intercropping systems in rainfed areas because AMF can form a common mycorrhizal network (CMN) that can transfer nutrients and water between two plants and balance as such belowground competition. In this study, we tested if biofertilizers can enhance the yield of intercropping systems using a pigeon pea (PP) - finger millet (FM) intercropping system grown for two consecutive growing seasons (2016/17 and 2017/18) at two contrasting sites in Bengaluru and Kolli Hills, India. To validate the process of bioirrigation (transfer of water between rhizosphere of two plants), we tested, for the first time, if the spatial arrangement of intercropped plants using either a row-wise or a mosaic design affected yield and water relations with and without biofertilizers. Our results demonstrate that intercropping can improve the straw and grain yield in PP-FM intercropping compared to the respective monocultures but that intercropping effects vary depending on the site characteristic such as climate and soil type. Spatial arrangement of component plants affected the total, straw and grain biomass in intercropping treatments, but this effect also varied across sites. Most importantly, the results from the 2017-18 growing season clearly demonstrated a positive effect of biofertilizer on biomass yield, and this effect was irrespective of site, spatial arrangement, mixed or monoculture. Despite a yield increase in intercropping, we did not see a positive effect of biofertilization on water relations of FM possibly due to interspecific competition for soil moisture where PP dominated. In summary, our study shows the potential of biofertilizers to increase the yield of intercropping systems in rainfed dryland agriculture.

ecology↗