Role of Root Morphological and Physiological Characteristics in Drought Resistance of Plants

Author(s):  
Bingru Huang
2021 ◽  
Author(s):  
Shumao Cui ◽  
Jie Jiang ◽  
Bowen Li ◽  
R. Paul Ross ◽  
Catherine Stanton ◽  
...  

The role of Pediococcus pentosaceus in gastrointestinne has received considerable attention in recent decades. This study aimed to investigate the effects of short-term administration of P. pentosaceus on physiological characteristics,...


2020 ◽  
Author(s):  
Svenja Stock ◽  
Moritz Köster ◽  
Jens Boy ◽  
Roberto Godoy ◽  
Francisco Nájera ◽  
...  

<p>Arbuscular mycorrhizal fungi (AMF) are important partners in plant nutrition, as they increase the range to scavenge for nutrients and can access resources otherwise occlude for plants. Under water shortage, when mobility of nutrients in soil is limited, AMF are especially important to acquire resources and can modulate plant drought resistance. Strategies of plants to cope with water and nutrient restrictions are shaped by the intensity of aridity. To investigate the effect of aridity on plant-AMF associations regarding drought resistance and plant nutrient acquisition, a <sup>13</sup>CO<sub>2</sub> pulse labeling was conducted across an aridity gradient. In a semiarid shrubland (66 mm a<sup>-1</sup>), a Mediterranean woodland (367 mm a<sup>-1</sup>), and a humid temperate forest (1500 mm a<sup>-1</sup>), root and soil samples were taken from 0-10 cm and 20-30 cm soil depth before labeling and at 1 day, 3 days, and 14 days after labeling. Carbon (C), nitrogen (N), and phosphorus (P) stocks as well as AMF root colonization, extraradical AMF biomass (phospho- and neutral lipid fatty acids (PLFA and NLFA) 16:1w5c), specific root length (SRL), and root tissue density (RTD) were measured. Plant C investment into AMF and roots was determined by the <sup>13</sup>C incorporation in 16:1w5c (PLFA and NLFA) and root tissue, respectively. Soil C:N:P stoichiometry indicated a N and P limitation under humid conditions and a P limitation in the topsoil under Mediterranean conditions. N stocks were highest in the Mediterranean woodland. A strong correlation of the AMF storage compound NLFA 16:1w5c to C:P ratio under semiarid conditions pointed to a P limitation of AMF, likely resulting from low P mobility in dry and alkaline soils. With increasing aridity, the AMF abundance in root (and soil) decreased from 45% to 20% root area. <sup>13</sup>C incorporation in PLFA 16:1w5c was similar across sites, while relative AMF abundance in topsoil (PLFA 16:1w5c:SOC) was slightly higher under semiarid and humid than under Mediterranean conditions, pointing to the importance of AMF for plant nutrition under nutrient limitation. Additionally, PLFA 16:1w5c contents in soil were higher with lower P availability in each site, underlining the role of AMF to supply P for plants under P deficiency. Under humid conditions (with strong N and P limitation) and semiarid conditions (with strong water limitation), root AMF colonization increased with lower N availability, displaying the role of AMF for plant N nutrition under nutrient and/or water shortage. Under humid and Mediterranean conditions, SRL decreased (0.5 and 0.3 times, respectively) and RTD increased (1.9 and 1.7 times, respectively) with depth, indicating a drought tolerance strategy of plants to sustain water shortage. Under semiarid conditions, SRL increased with depth (2.3 times), while RTD was consistently high, suggesting an increasing proportion of long-living fine roots with depth as scavenging agents for water. These relations point to a drought avoidance strategy of plants as adaptation to long-term water limitation. Under strong nutrient limitation, as under humid and semiarid conditions, AMF are crucial to sustain plant nutrition and to enhance plant resistance to water shortage.</p>


Author(s):  
Anh Thu Pham Thi ◽  
Jorge Vieira Da Silva ◽  
Paul Mazliak

1970 ◽  
Vol 48 (6) ◽  
pp. 1235-1241 ◽  
Author(s):  
P. A. Henckel

One of the major protective adaptations of plants in response to drought is their ability to renew proteins during drought and to repair themselves rapidly after drought, i.e. after exposure to a combination of increased temperature plus dehydration. Corn plants subjected to presowing hardening were used as a model of plants with increased drought resistance. Such plants have a more drought resistant ultrastructure and form more high-energy substances, which promote synthetic processes in them. In hardened plants, 15N incorporation into proteins during and after drought proceeds at a faster rate than in control plants. Also, their ribonuclease is less active with respect to messenger RNA (ribonucleic acid), and polysome degradation into ribosomes and subunits occurs more slowly during drought. Polysomes revert to normal after drought faster in hardened than in non-hardened plants. All this explains the greater resistance of plants exposed to presowing hardening.


2012 ◽  
Vol 448 (3) ◽  
pp. 353-363 ◽  
Author(s):  
Mi Jung Kim ◽  
Mi-Jeong Park ◽  
Pil Joon Seo ◽  
Jin-Su Song ◽  
Hie-Joon Kim ◽  
...  

Controlled proteolytic activation of membrane-anchored transcription factors provides an adaptation strategy that guarantees rapid transcriptional responses to abrupt environmental stresses in both animals and plants. NTL6 is a plant-specific NAC [NAM/ATAF1/2/CUC2] transcription factor that is expressed as a dormant plasma membrane-associated form in Arabidopsis. Proteolytic processing of NTL6 is triggered by abiotic stresses and ABA (abscisic acid). In the present study, we show that NTL6 is linked directly with SnRK (Snf1-related protein kinase) 2.8-mediated signalling in inducing a drought-resistance response. SnRK2.8 phosphorylates NTL6 primarily at Thr142. NTL6 phosphorylation by SnRK2.8 is required for its nuclear import. Accordingly, a mutant NTL6 protein, in which Thr142 was mutated to an alanine, was poorly phosphorylated and failed to enter the nucleus. In accordance with the role of SnRK2.8 in drought-stress signalling, transgenic plants overproducing either NTL6 or its active form 6ΔC (35S:NTL6 and 35S:6ΔC) exhibited enhanced resistance to water-deficit conditions such as those overproducing SnRK2.8 (35S:SnRK2.8). In contrast, NTL6 RNAi (RNA interference) plants were susceptible to dehydration as observed in the SnRK2.8-deficient snrk2.8-1 mutant. Furthermore, the dehydration-resistant phenotype of 35S:NTL6 transgenic plants was compromised in 35S:NTL6 X snrk2.8-1 plants. These observations indicate that SnRK2.8-mediated protein phosphorylation, in addition to a proteolytic processing event, is important for NTL6 function in inducing a drought-resistance response.


2021 ◽  
Author(s):  
Michael Thieme ◽  
Arthur Brêchet ◽  
Yann Bourgeois ◽  
Bettina Keller ◽  
Etienne Bucher ◽  
...  

Plant genomes comprise a vast diversity of transposable elements (TEs) (Tenaillon et al. 2010)⁠. While their uncontrolled proliferation can have fatal consequences for their host, there is strong evidence for their importance in fueling genetic diversity and plant evolution (Baduel et al. 2021)⁠. However, the number of studies addressing the role of TEs in this process is limited. Here we show that the heat-induced burst of a low-copy TE increases phenotypic diversity and leads to the rapid emergence of more drought-resistant individuals of Arabidopsis thaliana. We exposed TE-high-copy-(hc)lines (Thieme et al. 2017)⁠ with up to ~8 fold increased copy numbers of the heat-responsive ONSEN-TE (AtCOPIA78) (Ito et al. 2011; Cavrak et al. 2014; Tittel-Elmer et al. 2010)⁠ in the wild type background to desiccation as a straightforward and highly relevant selection pressure. We found evidence for a drastic increase of drought resistance in five out of the 23 tested hc-lines and further pinpoint one of the causative mutations to an exonic ONSEN-insertion in the ribose-5-phosphate-isomerase 2 gene. This loss-of-function mutation resulted in a decreased rate of photosynthesis and water consumption. This is one of the rare examples (Esnault et al. 2019)⁠ experimentally demonstrating the adaptive potential of mobilized stress-responsive TEs in eukaryotes. Our results further shed light on the complex relationship between mobile elements and their hosts and substantiate the importance of TE-mediated loss-of-function mutations in stress adaptation, particularly with respect to global warming.


Author(s):  
Fenghao Zhang ◽  
Jie Dai ◽  
Tingtao Chen

Infertility has become a common problem in recent decades. The pathogenesis of infertility is variable, but microbiological factors account for a large proportion of it. Dysbiosis of vaginal microbiota is reportedly associated with female infertility, but the influence of normal vaginal microbiota on infertility is unclear. In this review, we summarize the physiological characteristics of the vaginal tract and vaginal microbiota communities. We mainly focus on the bacterial adherence of vaginal Lactobacillus species. Given that the adherent effect plays a crucial role in the colonization of bacteria, we hypothesize that the adherent effect of vaginal Lactobacillus may also influence the fertility of the host. We also analyze the agglutination and immobilization effects of other bacteria, especially Escherichia coli, on ejaculated spermatozoa, and speculate on the possible effects of normal vaginal microbiota on female fertility.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pantelis T. Nikolaidis ◽  
Thomas Rosemann ◽  
Beat Knechtle

AimDespite the increasing popularity of outdoor endurance running races of different distances, little information exists about the role of training and physiological characteristics of recreational runners. The aim of the present study was (a) to examine the role of training and physiological characteristics on the performance of recreational marathon runners and (b) to develop a prediction equation of men’s race time in the “Athens Authentic Marathon.”MethodsRecreational male marathon runners (n = 130, age 44.1 ± 8.6 years)—who finished the “Athens Authentic Marathon” 2017—performed a series of anthropometry and physical fitness tests including body mass index (BMI), body fat percentage (BF), maximal oxygen uptake (VO2max), anaerobic power, squat, and countermovement jump. The variation of these characteristics was examined by quintiles (i.e., five groups consisting of 26 participants in each) of the race speed. An experimental group (EXP, n = 65) was used to develop a prediction equation of the race time, which was verified in a control group (CON, n = 65).ResultsIn the overall sample, a one-way ANOVA showed a main effect of quintiles on race speed on weekly training days and distance, age, body weight, BMI, BF, and VO2max (p ≤ 0.003, η2 ≥ 0.121), where the faster groups outscored the slower groups. Running speed during the race correlated moderately with age (r = −0.36, p < 0.001) and largely with the number of weekly training days (r = 0.52, p < 0.001) and weekly running distance (r = 0.58, p < 0.001), but not with the number of previously finished marathons (r = 0.08, p = 0.369). With regard to physiological characteristics, running speed correlated largely with body mass (r = −0.52, p < 0.001), BMI (r = −0.60, p < 0.001), BF (r = −0.65, p < 0.001), VO2max (r = 0.67, p < 0.001), moderately with isometric muscle strength (r = 0.42, p < 0.001), and small with anaerobic muscle power (r = 0.20, p = 0.021). In EXP, race speed could be predicted (R2 = 0.61, standard error of the estimate = 1.19) using the formula “8.804 + 0.111 × VO2max + 0.029 × weekly training distance in km −0.218 × BMI.” Applying this equation in CON, no bias was observed (difference between observed and predicted value 0.12 ± 1.09 km/h, 95% confidence intervals −0.15, 0.40, p = 0.122).ConclusionThese findings highlighted the role of aerobic capacity, training, and body mass status for the performance of recreational male runners in a marathon race. The findings would be of great practical importance for coaches and trainers to predict the average marathon race time in a specific group of runners.


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