scholarly journals Laser Microdissection of Pisum sativum L. Nodules Followed by RNA-Seq Analysis Revealed Crucial Transcriptomic Changes During Infected Cell Differentiation

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2504
Author(s):  
Pyotr G. Kusakin ◽  
Tatiana A. Serova ◽  
Natalia E. Gogoleva ◽  
Yuri V. Gogolev ◽  
Viktor E. Tsyganov

Garden pea (Pisum sativum L.) is a globally important legume crop. Like other legumes, it forms beneficial symbiotic interactions with the soil bacteria rhizobia, gaining the ability to fix atmospheric nitrogen. In pea nodules, the meristem is long-lasting and results in the formation of several histological zones that implicate a notable differentiation of infected host cells. However, the fine transcriptional changes that accompany differentiation are still unknown. In this study, using laser microdissection followed by RNA-seq analysis, we performed transcriptomic profiling in the early infection zone, late infection zone, and nitrogen fixation zone of 11-day-old nodules of pea wild-type line SGE. As a result, a list of functional groups of differentially expressed genes (DEGs) in different nodule histological zones and a list of genes with the most prominent expression changes during nodule development were obtained. Their analyses demonstrated that the highest amount of DEGs was associated with the nitrogen fixation zone. Among well-known genes controlling nodule development, we revealed genes that can be novel players throughout nodule formation. The characterized genes in pea were compared with those previously described in other legumes and their possible functions in nodule development are discussed.

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 56
Author(s):  
Elizaveta S. Rudaya ◽  
Polina Yu. Kozyulina ◽  
Olga A. Pavlova ◽  
Alexandra V. Dolgikh ◽  
Alexandra N. Ivanova ◽  
...  

The IPD3/CYCLOPS transcription factor was shown to be involved in the regulation of nodule primordia development and subsequent stages of nodule differentiation. In contrast to early stages, the stages related to nodule differentiation remain less studied. Recently, we have shown that the accumulation of cytokinin at later stages may significantly impact nodule development. This conclusion was based on a comparative analysis of cytokinin localization between pea wild type and ipd3/cyclops mutants. However, the role of cytokinin at these later stages of nodulation is still far from understood. To determine a set of genes involved in the regulation of later stages of nodule development connected with infection progress, intracellular accommodation, as well as plant tissue and bacteroid differentiation, the RNA-seq analysis of pea mutant SGEFix--2 (sym33) nodules impaired in these processes compared to wild type SGE nodules was performed. To verify cytokinin’s influence on late nodule development stages, the comparative RNA-seq analysis of SGEFix--2 (sym33) mutant plants treated with cytokinin was also conducted. Findings suggest a significant role of cytokinin in the regulation of later stages of nodule development.


Author(s):  
Swarup Roy Choudhury ◽  
Sarah M. Johns ◽  
Sona Pandey

Legumes develop root nodules that harbour endosymbiotic bacteria, rhizobia. These rhizobia convert nitrogen to ammonia by biological nitrogen fixation. A thorough understanding of the biological nitrogen fixation in legumes and its regulation is key to develop sustainable agriculture. It is well known that plant hormones affect nodule formation; however, most studies are limited to model legumes due to their suitability for in vitro, plate-based assays. Specifically, it is almost impossible to measure the effects of exogenous hormones or other additives during nodule development in crop legumes such as soybean as they have huge root system in soil. To circumvent this issue, the present research develops suitable media and growth conditions for efficient nodule development under in vitro, soil free conditions in an important legume crop, soybean. Moreover, we also evaluate the effects of all major phytohormones during soybean nodulation under identical conditions. This versatile, inexpensive, scalable and simple protocol provides several advantages over previously established methods. It is extremely time-and resource-efficient, does not require special training or equipment, and produces highly reproducible results. The approach is expandable to other large legumes as well as for other exogenous additives.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Krista L. Plett ◽  
Sean L. Bithell ◽  
Adrian Dando ◽  
Jonathan M. Plett

Abstract Background The ability of chickpea to obtain sufficient nitrogen via its symbiotic relationship with Mesorhizobium ciceri is of critical importance in supporting growth and grain production. A number of factors can affect this symbiotic relationship including abiotic conditions, plant genotype, and disruptions to host signalling/perception networks. In order to support improved nodule formation in chickpea, we investigated how plant genotype and soil nutrient availability affect chickpea nodule formation and nitrogen fixation. Further, using transcriptomic profiling, we sought to identify gene expression patterns that characterize highly nodulated genotypes. Results A study involving six chickpea varieties demonstrated large genotype by soil nitrogen interaction effects on nodulation and further identified agronomic traits of genotypes (such as shoot weight) associated with high nodulation. We broadened our scope to consider 29 varieties and breeding lines to examine the relationship between soilborne disease resistance and the number of nodules developed and real-time nitrogen fixation. Results of this larger study supported the earlier genotype specific findings, however, disease resistance did not explain differences in nodulation across genotypes. Transcriptional profiling of six chickpea genotypes indicates that genes associated with signalling, N transport and cellular localization, as opposed to genes associated with the classical nodulation pathway, are more likely to predict whether a given genotype will exhibit high levels of nodule formation. Conclusions This research identified a number of key abiotic and genetic factors affecting chickpea nodule development and nitrogen fixation. These findings indicate that an improved understanding of genotype-specific factors affecting chickpea nodule induction and function are key research areas necessary to improving the benefits of rhizobial symbiosis in chickpea.


2002 ◽  
Vol 80 (9) ◽  
pp. 907-915 ◽  
Author(s):  
Walter F Giordano ◽  
Michelle R Lum ◽  
Ann M Hirsch

We have initiated studies on the molecular biology and genetics of white sweetclover (Melilotus alba Desr.) and its responses to inoculation with the nitrogen-fixing symbiont Sinorhizobium meliloti. Early nodulin genes such as ENOD40 serve as markers for the transition from root to nodule development even before visible stages of nodule formation are evident. Using Northern blot analysis, we found that the ENOD40 gene was expressed within 6 h after inoculation with two different strains of S. meliloti, one of which overproduces symbiotic Nod factors. Inoculation with this strain resulted in an additional increase in ENOD40 gene expression over a typical wild-type S. meliloti strain. Moreover, the increase in mRNA brought about by the Nod-factor-overproducing strain 24 h after inoculation was correlated with lateral root formation by using whole-mount in situ hybridization to localize ENOD40 transcripts in lateral root meristems and by counting lateral root initiation sites. Cortical cell divisions were not detected. We also found that nodulation occurred more rapidly on white sweetclover in response to the Nod-factor-overproducing strain, but ultimately there was no difference in nodulation efficiency in terms of nodule number or the number of roots nodulated by the two strains. Also, the two strains could effectively co-colonize the host when inoculated together, although a few host cells were occupied by both strains.Key words: ENOD40, Nod factor, Melilotus, Sinorhizobium, symbiosis.


2017 ◽  
Vol 9 (3) ◽  
pp. 22-35 ◽  
Author(s):  
E. A. Dolgikh ◽  
A. I. Shaposhnikov ◽  
A. V. Dolgikh ◽  
E. S. Gribchenko ◽  
K. B. Bodyagina ◽  
...  

1974 ◽  
Vol 25 (4) ◽  
pp. 577 ◽  
Author(s):  
A Diatloff

Root nodules formed on Tinaroo glycine (Glycine wightii) were slow to pigment and begin fixing nitrogen. Various carbon and nitrogen compounds enhanced nodule pigmentation, the greening of the plants, and the rate of nitrogen fixation at 42 days. Of these inositol, glucose, ammonium nitrate (as both foliar and root applications) and coconut milk were most effective. Riboflavin, sodium glutamate and nodule infusion had little effect. There were no structural differences between nodules enhanced respectively by glucose and ammonium nitrate. Nodules on control plants showed slow development of the bacteroids and envelope membranes, with copious starch accumulation in uninvaded host cells. It was concluded that the retarded symbiosis in formed nodules was due initially to tardy nodule formation depleting the nitrogen reserves in the seeds before nitrogen fixation began. Because of the interaction of photosynthesis and nitrogen fixation, self-regeneration of nitrogen fixation in chlorotic plants was slow without an external stimulus. It is suggested that by selecting lines of the legume with larger seeds or by incorporating nitrogen in seed pellets the problem might be overcome.


Sign in / Sign up

Export Citation Format

Share Document