scholarly journals A comparative study of genomic adaptations to low nitrogen availability in Genlisea aurea

2021 ◽  
Author(s):  
Thibaut Goldsborough

AbstractGenlisea aurea is a carnivorous plant that grows on nitrogen-poor waterlogged sandstone plateaus and is thought to have evolved carnivory as an adaptation to very low nitrogen levels in its habitat. The carnivorous plant is also unusual for having one of the smallest genomes among flowering plants. Genomic DNA is known to have a high nitrogen content and yet, to the author’s knowledge, no published study has linked nitrogen starvation of G. aurea with genome size reduction. This comparative study of the carnivorous plant G. aurea, the model organism Arabidopsis thaliana (Brassicaceae) and the nitrogen fixing Trifolium pratense (Fabaceae) attempts to investigate whether the genome, transcriptome and proteome of G. aurea showed evidence of adaptations to low nitrogen availability. It was found that although G. aurea’s genome, CDS and non-coding DNA were much lower in nitrogen than the genome of T. pratense and A. thaliana this was solely due to the length of the genome, CDS and non-coding sequences rather than the composition of these sequences.

2019 ◽  
Vol 12 (5) ◽  
pp. 815-824
Author(s):  
Yong Zhou ◽  
Xia Li ◽  
Hui Liu ◽  
Yubao Gao ◽  
Wade J Mace ◽  
...  

Abstract Aims The leaves of almost all terrestrial plant species are colonized by endophytic fungi. Compared to agronomic grasses, which usually harbor few endophytes, native grasses generally possess greater endophyte species diversity. Existing studies examining endophyte effects on natural grasses under competition normally considered the infection status (infected or uninfected), and rarely considered endophyte species. Methods We examined the effects of endophyte infection and of endophyte species on the interspecific competitive ability of a subdominant species, Achnatherum sibiricum, at two nitrogen levels (high nitrogen and low nitrogen). Achnatherum sibiricum plants infected by two different species of endophyte (Epichloë sibirica and E. gansuensis) and uninfected plants were grown in monoculture and binary mixtures with a dominant species, Stipa grandis (six individuals per species for monocultures and three + three individuals of each species in mixtures). Shoot and root biomass, tiller number and total phenolic concentration were measured after 3 months. Moreover, the aggressivity index was calculated to compare the competitive ability of A. sibiricum relative to S. grandis. Important Findings Both E. gansuensis (Eg)- and E. sibirica (Es)-infected A. sibiricum plants showed a greater competitive ability than the uninfected plants under high nitrogen supply, while the opposite result occurred under low nitrogen supply. At high nitrogen levels, Eg plants had a higher tiller number and a greater shoot biomass inhibitory effect on S. grandis than Es plants had when growing in mixture, while Es plants showed better root growth performance than Eg and uninfected plants under mixture conditions at all nitrogen levels. A higher concentration of phenolic compounds in Eg plants than in Es plants might contribute to the higher inhibitory effect of Eg plants on competing plants. Our study indicates that the interaction between endophyte infection and nitrogen availability can alter the competitive ability of the host plant A. sibiricum but that these two endophyte species work in different ways, which may influence the coexistence of A. sibiricum with the dominant species.


2019 ◽  
Vol 20 (23) ◽  
pp. 5893 ◽  
Author(s):  
Wei Xin ◽  
Lina Zhang ◽  
Wenzhong Zhang ◽  
Jiping Gao ◽  
Jun Yi ◽  
...  

Nitrogen is an essential nutrient for plant growth and basic metabolic processes. Root systems play an important role in the ability of plants to obtain nutrients from the soil, and are closely related to the growth and development of above-ground plants. Root morphology analysis showed that root growth was induced under low-nitrogen conditions and inhibited under high-nitrogen conditions. To better understand the molecular mechanisms and metabolic basis underlying the rice root response to nitrogen availability, an integrated analysis of the rice root transcriptome and metabolome under three environmental conditions (low-, control, and high-nitrogen conditions) was conducted. A total of 262 and 262 differentially level metabolites were identified under low- and high-nitrogen conditions, respectively. A total of 696 and 808 differentially expressed genes were identified under low- and high-nitrogen conditions, respectively. For both the differentially expressed genes and metabolites, KEGG pathway analysis indicated that amino acid metabolism, carbon and nitrogen metabolism, phenylpropanoid metabolism, and phytohormones’ signal transduction were significantly affected by nitrogen availability. Additionally, variable levels of 65 transcription factors (TFs) were identified in rice leaves exposed to high and low nitrogen, covering 22 TF families. These results also indicate that there is a significant difference in the transcriptional regulation mechanisms of rice roots between low and high nitrogen. In summary, our study provides new information for a further understanding of the response of rice roots to low-nitrogen and high-nitrogen conditions.


1958 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
LF Myers ◽  
J Lipsett

The effect of skeleton weed competition on the yield of wheat and oats was investigated in seasons when rainfall was plentiful. Nitrogen was found to be the major factor limiting crop yields. In soils with comparable nitrogen-supplying powers, skeleton weed density governed the crop's response to applied nitrogen. Competition between skeleton weed and crop was severe at low nitrogen levels, but minor at the high nitrogen levels achieved either by nitrogen application, or when the crop followed a legume-rich pasture. Competition had its effect early in the crop's growth. Temporary removal of competition, by spraying with plant growth regulating substances (JICPA) at different times, was used to determine when competition was critical, and measure its effects. Skeleton weed reduced nitrogen supply early in the crop's growth, and so depressed yield. An application of 1 lb MCPA per acre in the fallow 54 days before sowing, or 10 days after crop emergence, increased the yield of oats from 710 to 1350 lb grain per acre: a response equal to that from 32 lb nitrogen per acre applied at planting in the same experiment. In each case, the response to spraying at the different times was analogous to the effect of a nitrogen application at these times. Early spraying gave responses in yield; later spraying gave responses in grain nitrogen. The results provide a new estimate of the reduction in crop yield due to skeleton weed.


1951 ◽  
Vol 29 (5) ◽  
pp. 297-304 ◽  
Author(s):  
D. S. Smith ◽  
F. E. Northcott

Melanoplus mexicanus mexicanus (Sauss.), from time of hatching, was fed on wheat (Renown) grown in nutrient solutions of varying nitrogen content. Some wheat was produced with an average nitrogen content of 6.16% (dry weight), some with 4.29%, and some with 3.33%. Survival and development were greatest on the high nitrogen wheat, least on the low. On the low nitrogen wheat no individuals developed beyond the last nymphal instar. Neither weight of adults nor the sex ratio was affected by the various foods. Females fed on wheat with a high nitrogen content laid more eggs but the viability of the eggs was not affected.


2002 ◽  
Vol 29 (7) ◽  
pp. 787 ◽  
Author(s):  
Masaharu C. Kato ◽  
Kouki Hikosaka ◽  
Tadaki Hirose

Involvement of photosynthetic capacity and D1 protein turnover in the susceptibility of photosystem II (PSII) to photoinhibition was investigated in leaves of Chenopodium album L. grown at different combinations of irradiance and nitrogen availability: low light and high nitrogen (LL-HN); high light and low nitrogen (HL-LN); and high light and high nitrogen (HL-HN). To test the importance of photosynthetic capacity in the susceptibility to photoinhibition, we adjusted growth conditions so that HL-HN plants had the highest photosynthetic capacity, while that of LL-HN and HL-LN plants was lower but similar to each other. Photoinhibition refers here to net inactivation of PSII determined by the balance between gross inactivation (photoinactivation) and concurrent recovery of PSII via D1 protein turnover. Leaves were illuminated both in the presence and absence of lincomycin, an inhibitor of chloroplast-encoded protein synthesis. Susceptibility to photoinhibition was much higher in plants grown in low light (LL-HN) than those grown in high light (HL-HN and HL-LN). Susceptibility to photoinhibition was similar in HL-LN and HL-HN plants, suggesting that higher photosynthetic energy consumption alone did not mitigate photoinhibition. Experiments with and without lincomycin showed that high-light-grown plants had a lower rate of photoinactivation and a higher rate of concurrent recovery, and that these rates were not influenced by nitrogen availability. These results indicate that turnover of D1 protein plays a crucial role in photoprotection in high-light-grown plants, irrespective of nitrogen availability. For low-nitrogen-grown plants, higher light energy dissipation by other mechanisms may have compensated for lower energy utilization by photosynthesis.


2021 ◽  
Author(s):  
Nadia Herrera ◽  
Pascal D Odermatt ◽  
Mark Voorhies ◽  
Rachel Nakagawa ◽  
Anita Sil ◽  
...  

The ESX-1 system (6-kDa early secretory antigenic target (ESAT-6) secretion system-1) is essential for Mycobacterium tuberculosis pathogenesis and conjugal transfer in Mycobacterium smegmatis, yet little is known about how its function is regulated. Live-cell fluorescence microscopy showed natively expressed ESX-1 was organized into distinct foci predominantly observed at cell-cell contacts. These foci formed when two cells touched and required a fully assembled ESX-1 system in both bacteria, suggesting the generation of an ESX-1 megacomplex across multiple membranes. The emergence of ESX-1 foci and ESX-1 secretion was environmentally dependent: foci formed in low nitrogen environments in which secretion was suppressed, yet with increasing concentrations of nitrogen, ESX-1 systems diffused along the plasma membrane and secretion was activated. Genome-wide transcriptional profiling revealed ESX-1 dependent induction of genes required for the SOS response and error prone DNA replication in high nitrogen. Based on these findings, we propose a new model of ESX-1 function where ESX-1 localization and secretion are responsive to nitrogen levels and form an integral node in the mycobacterial response to neighboring cells and environmental adaptation.


Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 847-853 ◽  
Author(s):  
Kimberly D. Tungate ◽  
Michael G. Burton ◽  
David J. Susko ◽  
Shannon M. Sermons ◽  
Thomas W. Rufty

The low-nitrogen status of highly weathered soils may offer a potential alternative for weed suppression in agricultural systems with N2-fixing crops. In this study, we used sicklepod as a model to evaluate weed response that might occur with managed reductions in nitrogen-soil fertility. A field study was conducted with the parental generation supplied 0, 112, 224, or 448 kg N ha−1. Decreased nitrogen fertility led to reduced shoot biomass, seed number, and total seed mass. Individual seed mass was lower, but seed % nitrogen was not affected. Analysis of seed-mass distribution confirmed that low parental fertility was associated with more small seeds as a proportion of total seeds produced. Additional experiments in hydroponics culture revealed slower growth rates of seedlings produced from small seeds when grown under low-nitrogen conditions. Competitiveness of plants from small (low nitrogen) and large (high nitrogen) seed classes was determined in a replacement-series experiment conducted in sand culture in a controlled environment at two densities and two levels of nitrogen nutrition. Plants produced from smaller seeds were less competitive in low-nitrogen fertility conditions, but plants from small and large seeds competed similarly when grown under high-nitrogen fertility. The results support the hypothesis that comprehensive management strategies to reduce nitrogen availability for weed growth in low-fertility conditions could decrease weed interference by decreasing growth and seed production of parental plants and through maternal effects that lower competitiveness of offspring.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lihua Zhang ◽  
Simin Sun ◽  
Yonghui Liang ◽  
Baiyun Li ◽  
Songya Ma ◽  
...  

To comprehensively understand the responses of carbohydrate metabolism and transport to different levels of nitrogen supply in growing shoot tips of crabapple (Malus hupehensis Rehd), enzyme activities and related genes involved in the sugar metabolism pathway were investigated. The nitrogen and chlorophyll content of plants increased with increasing nitrogen supply. High nitrogen application increased the net photosynthesis rate and the growth rate of shoot tips but decreased the synthesis capability of sucrose and sorbitol in mature leaves. However, the shoot tips of plants under high-nitrogen treatment had higher contents of sucrose and sorbitol than did those under low-nitrogen treatment, while the activity of sucrose phosphate synthase and aldose-6-phosphate was increased and the transporters MdSOT and MdSUT were up-regulated. Moreover, the activities of enzymes involved in sucrose and hexose metabolism (including sucrose synthase, fructokinase, and hexokinase) were enhanced in the shoot tips of plants under high-nitrogen conditions, and the expression levels of MdSUSY3 and MdHK1 were significantly up-regulated. These findings indicate that a high nitrogen supply increases the metabolic capacity of assimilatory substances in shoot tips, accelerates the efficiency of sugar utilization and eventually leads to a rapid increase in the growth of shoot tips. Our results highlight that high nitrogen increases the capacity of sugar unloading and metabolic utilization in growing shoot tissues.


EDIS ◽  
2013 ◽  
Vol 2013 (11) ◽  
Author(s):  
Michael A. Davis ◽  
Doug R. Sloan ◽  
Gerald Kidder ◽  
R. D. Jacobs

Animal manures have been used as natural crop fertilizers for centuries. Because of poultry manure’s high nitrogen content, it has long been recognized as one of the most desirable manures. Besides fertilizing crops, manures also supply other essential plant nutrients and serve as a soil amendment by adding organic matter, which helps improve the soil’s moisture and nutrient retention. Organic matter persistence will vary with temperature, drainage, rainfall, and other environmental factors. This 2-page fact sheet was written by Michael A. Davis, D.R. Sloan, Gerald Kidder, and R.D. Jacobs, and published by the UF Department of Animal Science, November 2013. http://edis.ifas.ufl.edu/aa205


2021 ◽  
Vol 22 (15) ◽  
pp. 8085
Author(s):  
Liuqing Huo ◽  
Zijian Guo ◽  
Qi Wang ◽  
Li Cheng ◽  
Xin Jia ◽  
...  

Autophagy is a conserved degradation pathway for recycling damaged organelles and aberrant proteins, and its important roles in plant adaptation to nutrient starvation have been generally reported. Previous studies found that overexpression of autophagy-related (ATG) gene MdATG10 enhanced the autophagic activity in apple roots and promoted their salt tolerance. The MdATG10 expression was induced by nitrogen depletion condition in both leaves and roots of apple plants. This study aimed to investigate the differences in the growth and physiological status between wild type and MdATG10-overexpressing apple plants in response to nitrogen starvation. A hydroponic system containing different nitrogen levels was used. The study found that the reduction in growth and nitrogen concentrations in different tissues caused by nitrogen starvation was relieved by MdATG10 overexpression. Further studies demonstrated the increased root growth and the higher nitrogen absorption and assimilation ability of transgenic plants. These characteristics contributed to the increased uptake of limited nitrogen nutrients by transgenic plants, which also reduced the starvation damage to the chloroplasts. Therefore, the MdATG10-overexpressing apple plants could maintain higher photosynthetic ability and possess better growth under nitrogen starvation stress.


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