Cotton Root Research Articles

A cotton APS REDUCTASE represses root hair elongation via sulfur assimilation and hydrogen peroxide‐mediated cell wall damage

AbstractSulfur is a critical element for plant growth and development, and it is assimilated through a pathway called the sulfur assimilation pathway. APS REDUCTASE (APR) is a key rate‐limiting enzyme in this pathway, and it plays a vital role in regulating sulfur flow and plant development. However, the exact role and mechanism of APR in cotton fiber and root hair development are still not fully understood. This study used in vitro cultured ovules grown on a sulfur‐deficient medium to explore the role of sulfur in fiber development. Genetic approaches such as virus‐induced gene silencing (VIGS) was used to determine the role of target genes. In vitro assays revealed the role of sulfur in fiber development and identified GhAPR2 as a key candidate gene. The GhAPR2 negatively regulates fiber cell initiation and Arabidopsis root hair elongation. Further studies demonstrated that overexpression of GhAPR2 increased the contents of sulfite and GSH to enhance sulfur assimilation in Arabidopsis, leading to abnormal accumulation of ROS in root hair. This down‐regulates the transcription of proline‐rich cell wall protein‐coding genes such as AtEXTs and AtPRPs, reducing the content of hydroxyproline in the cell wall, disrupting the development of the root hair cell wall, and inhibiting root hair elongation. This study elucidated the functional pathway of APR2 in the regulation of root hair development. APR2 first affects sulfur assimilation, which affects the content of reactive oxygen species (ROS), and finally affects the content of hydroxyproline‐rich glycoprotein, which in turn affects the development of root hair. This model also contributes to the understanding of the role of sulfur in fiber development, as well as cell differentiation and development.

Improved Transformer for Time Series Senescence Root Recognition.

The root is an important organ for plants to obtain nutrients and water, and its phenotypic characteristics are closely related to its functions. Deep-learning-based high-throughput insitu root senescence feature extraction has not yet been published. In light of this, this paper suggests a technique based on the transformer neural network for retrieving cotton's insitu root senescence properties. High-resolution insitu root pictures with various levels of senescence are the main subject of the investigation. By comparing the semantic segmentation of the root system by general convolutional neural networks and transformer neural networks, SegFormer-UN (large) achieves the optimal evaluation metrics with mIoU, mRecall, mPrecision, and mF1 metric values of 81.52%, 86.87%, 90.98%, and 88.81%, respectively. The segmentation results indicate more accurate predictions at the connections of root systems in the segmented images. In contrast to 2 algorithms for cotton root senescence extraction based on deep learning and image processing, the insitu root senescence recognition algorithm using the SegFormer-UN model has a parameter count of 5.81 million and operates at a fast speed, approximately 4 min per image. It can accurately identify senescence roots in the image. We propose that the SegFormer-UN model can rapidly and nondestructively identify senescence root in insitu root images, providing important methodological support for efficient crop senescence research.

Method for accounting subsoil moisture in drip irrigation

The study emphasizes the critical role of irrigation in food safety, particularly in regions facing agricultural sustainability challenges. Conventional water management practices hinder a sustainable progress. The adoption of drip irrigation, delivering water directly to plant roots is proposed as a viable solution. The findings reveal a significant reduction (10-50%) in irrigation rates and increase in cotton yields. Groundwater levels impact irrigation requirements, with higher levels correlating with increased rates. Calculations highlight varying groundwater uptake and soil moisture content based on the cotton root system’s depth.

Unravelling the Functional Role of GthGAPC2 in Cotton's Defense Against Verticillium dahliae through Proteome

AbstractCotton (Gossypium spp.) is an economically important crop, but its productivity is often hindered by the soil‐borne pathogen Verticillium dahliae. This study aimed to investigate the response of cotton roots to V. dahliae infection by analysing the proteome of Gossypium thurberi (resistant) and Gossypium raimondii (susceptible) at 0 h, 24 h, and 48 h post‐infection. Through weighted protein coexpression network analysis, fifteen hub proteins crucial for defense against V. dahliae were identified. Expression analysis revealed the pivotal role of GthGAPC2, encoding GLYCERALDEHYDE‐3‐PHOSPHATE DEHYDROGENASE 2, in conferring resistance to V. dahliae in cotton. Virus‐induced gene Silencing (VIGS) of GthGAPC2 increased susceptibility to V. dahliae, which was supported by oxidant and antioxidant enzyme activities. Furthermore, GthGAPC2 silencing influenced lignin content, indicating its involvement in lignin biosynthesis regulation. Transient overexpression of GthGAPC2 in tobacco supported its role in cell death processes. Subcellular localization studies showed predominant nuclear localization of GthGAPC2. Overexpression of GthGAPC2 in Arabidopsis also confirms its significant role in V. dahliae resistance. These findings shed light on the molecular mechanisms of disease resistance in Gossypium thurberi. Identification of GthGAPC2, as a key protein involved in V. dahliae resistance, and its functional implications can aid breeding strategies for enhancing cotton's disease resistance.

Distribution and accumulation of Cadmium in different trophic levels affecting Serangium japonicum, the predatory beetle of whitefly Bemisia tabaci, biologically, physiologically and genetically: An experimental study

Cadmium (Cd) is a heavy metal that is of great concern in agroecosystems due to its toxicity to plants, herbivores, carnivores, and human beings. The current study evaluated the allocation and bioaccumulation of Cd from soil to cotton plants, cotton plants to herbivore pests, and herbivorous pests to a natural enemy predator. When soil was spiked with 100 mg/kg Cd, results demonstrated that cotton roots accumulated more Cd than the stems and leaves. The bioaccumulation of Cd was less in 4th instar larvae, pupa, and adults of Serangium japonicum than in Bemisia tabaci adults. The bioaccumulation in S. japonicum elongated the immature development period and reduced adult longevity, oviposition days, fertility, and total pre-oviposition duration. The net reproduction of S. japonicum was also reduced, as was female mature weight and feeding potential; as a result, Cd exposure could reduce the future population size compared to uncontaminated populations. There was decreased activity of the antioxidant enzymes (SOD, CAT, and POD) and energy-conserving lipids (glycogen, triglyceride, and total cholesterol) in Cd-contaminated S. japonicum compared to controls. The detoxifying enzyme activity of GST and P450 increased while AChE activity did not change. The qRT-PCR research showed that SOD1, CAT, POD, glycogen, and triglyceride gene expression was higher than in controls, whereas detoxification gene expression did not change. Our results indicate that Cd exposure has a physiological trade-off between its adverse effects on life history traits and elevated detoxification and antioxidation of S. japonicum, which could result from gene expression alteration. Further studies are needed to assess whether Cd exposure causes irreversible DNA damage in S. japonicum.

Wall-associated kinase GhWAK13 mediates arbuscular mycorrhizal symbiosis and Verticillium wilt resistance in cotton.

The cell wall is the major interface for arbuscular mycorrhizal (AM) symbiosis. However, the roles of cell wall proteins and cell wall synthesis in AM symbiosis remain unclear. We reported that a novel wall-associated kinase 13 (GhWAK13) positively regulates AM symbiosis and negatively regulates Verticillium wilt resistance in cotton. GhWAK13 transcription was induced by AM symbiosis and Verticillium dahliae (VD) infection. GhWAK13 is located in the plasma membrane and expressed in the arbuscule-containing cortical cells of mycorrhizal cotton roots. GhWAK13 silencing inhibited AM colonization and repressed gene expression of the mycorrhizal pathway. Moreover, GhWAK13 silencing improved Verticillium wilt resistance and triggered the expression of immunity genes. Therefore, GhWAK13 is considered an immune suppressor required for AM symbiosis and disease resistance. GhWAK7A, a positive regulator of Verticillium wilt resistance, was upregulated in GhWAK13-silenced cotton plants. Silencing GhWAK7A improved AM symbiosis. Oligogalacturonides application also suppressed AM symbiosis. Finally, GhWAK13 negatively affected the cellulose content by regulating the transcription of cellulose synthase genes. The results of this study suggest that immunity suppresses AM symbiosis in cotton. GhWAK13 affects AM symbiosis by suppressing immune responses.

Water Consumption Structure and Root Water Absorption Source of an Oasis Cotton Field in an Arid Area of China

This research, conducted at the National Field Science Observation and Research Station of the Aksu Farmland Ecosystem in Xinjiang, was performed to partition evapotranspiration components, identify the main water absorption depth, and quantify the contribution of soil water at different depths during different growing stages of cotton by combining hydrogen and oxygen stable isotopes and the MixSIAR model. The results indicated that evapotranspiration in the seeding stage, bud stage, flowering and boll stage, boll opening stage, and harvesting stage were 88 mm, 137 mm, 542 mm, 214 mm, and 118 mm, respectively, and the corresponding transpiration accounted for 51%, 82%, 88%, 85%, and 72% of evapotranspiration. With the development of cotton roots, the water absorption depth gradually increased, and the main absorption depths in the late bud stage, mid flowering and boll stage, late flowering and boll stage, boll opening stage, and harvesting stage were 0–20 cm, 40–60 cm, 60–80 cm, 80–100 cm, and 0–20 cm, respectively, with corresponding contributions of 35.4%, 40.9%, 27.7%, 29.9%, and 22.5%. Our results can provide a theoretical foundation for the accurate irrigation management of cotton fields.

Simulation of soil water, heat, and salt adsorptive transport under film mulched drip irrigation in an arid saline-alkali area using HYDRUS-2D

The film mulched drip irrigation (FMDI) in severe drought and salinity areas makes the transport of water, heat, and salt in the soil more complicated. In this paper, two-year field experiments were carried out in southern Xinjiang from 2020 to 2021 (Salt levels: 0.2%, 0.4%, and 0.6%; Irrigation levels: 30 mm and 45 mm (2020). 22.5 mm, 30 mm, 37.5 mm, and 45 mm (2021)). Using the measured data of soil moisture, heat, and salinity, the HYDRUS-2D model was calibrated and validated, and the effects of soil adsorption on the simulation results were compared. Meanwhile, six irrigation scenarios were designed (The three levels of irrigation times were 8 times, 10 times, and 12 times. The total irrigation amounts were 360 mm and 450 mm). The results indicate that the simulated results of salt transport under the condition of kinetic adsorption matched accurately with the observed data (the maximum of RMSE was 0.293 ds m−1, and the minimum values of R2 and d were 0.923 and 0.934, respectively); similarly, the simulation results of soil water and heat transport were acceptable (the maximum values of RMSE were 0.033 cm cm−1 and 1.897 °C, and the minimum values of R2 and d were 0.877, 0.99 and 0.915, 0.807, respectively). The scenario simulation indicate that salt leaching mainly occurred under plastic film, the desalination in the 0–40 cm soil layer was obvious (The rate range of salt leaching is 29.8∼58.8%), and salt accumulation appeared in the 40–100 cm layer under plastic film in the specific scenarios. Considering the optimal desalination in the cotton root zone, the irrigation mode with 8 irrigation times (The irrigation interval of 12 d during the budding period, 2 times; the irrigation interval of 8 d, 6 times) with a total irrigation amount of 450 mm was recommended, which provides a reference for the regulation of water, heat, and salt in severe drought and salinity areas.

Gossypol Affects Viral Replication by Inhibiting Pseudorabies Virus Adsorption

Pseudorabies virus (PRV) has spread widely in swine herds since it was introduced into China, and PRV variants have appeared in many regions in China since 2011. Owing to the ongoing emergence of viral mutations, the protective efficacy of PRV vaccines faces great challenges. Gossypol is a polyphenolic natural compound purified from cotton roots, stems, or seeds. This study found that gossypol has a notable inhibitory effect on PRV. Based on the biological effects of gossypol, the anti-PRV effect of gossypol was studied from the aspects of mitochondrial damage, reactive oxygen species, energy metabolism, and autophagy. The results showed that gossypol had no direct inactivation effect on PRV in solution within concentrations of ≤3 µM; gossypol did not stimulate interferon-β to exert an anti-PRV effect by triggering mitochondrial DNA leakage; the anti-PRV effect of gossypol was reactive oxygen species and ATP-independent in cells; and the PRV-inhibitory effect of gossypol was independent of its induced autophagy. By adding gossypol to PRV-infected cells at different stages of infection and performing virus titer detection, atomic force microscopy, qPCR, fluorescence microscopy, and firefly luciferase activity assays, we found that gossypol exerted an anti-PRV effect by inhibiting the adsorption of PRV on the cell surface.

Investigating Verticillium wilt occurrence in cotton and its risk management by the direct return of cotton plants infected with Verticillium dahliae to the field.

Verticillium wilt is one of the most crucial diseases caused by Verticillium dahliae that threatens the cotton industry. Statistical results showed that the return of cotton plants infected with V. dahliae to the field might be an essential cause of the continuous aggravation of cotton Verticillium wilt. The correlation among the cotton plants infected with V. dahliae returning to the field, the occurrence of Verticillium wilt, and the number of microsclerotia in rhizosphere soil need further investigation. A potted experiment was carried out to explore the effects of the direct return of cotton plants infected with Verticillium dahliae to the field on the subsequent growth and Verticillium wilt occurrence in cotton. As a risk response plan, we investigated the feasibility of returning dung-sand (i.e., insect excreta) to the field, the dung-sand was from the larvae of Protaetia brevitarsis (Coleoptera: Cetoniidea) that were fed with the V. dahliae-infected cotton plants. The results demonstrated that the return of the entire cotton plants to the field presented a promotional effect on the growth and development of cotton, whereas the return of a single root stubble or cotton stalks had an inhibitive effect. The return of cotton stalks and root stubble infected with V. dahliae increased the risk and degree of Verticillium wilt occurrence. The disease index of Verticillium wilt occurrence in cotton was positively correlated with the number of microsclerotia in the rhizosphere soil. The disease index increased by 20.00%, and the number of soil microsclerotia increased by 8.37 fold in the treatment of returning root stubble infected with V. dahliae to the field. No Verticillium wilt microsclerotia were detected in the feed prepared from cotton stalks and root stubble fermented for more than 5 days or in the transformed dung-sand. There was no risk of inoculation with Verticillium wilt microsclerotia when the dung-sand was returned to the field. The indirect return of cotton plants infected with V. dahliae to the field by microorganism-insect systems is worthy of further exploration plan of the green prevention and control for Verticillium wilt and the sustainable development of the cotton industry.

Transcriptional landscape of cotton roots in response to salt stress at single-cell resolution

Increasing soil salinization has led to severe reductions in plant yield and quality, and investigating the molecular mechanism of salt stress response is therefore an urgent priority. In this study, we systematically analyzed the response of cotton roots to salt stress using single-cell transcriptomics technology; 56 281 high-quality cells were obtained from 5-day-old lateral root tips of Gossypium arboreum under natural growth conditions and different salt treatments. Ten cell types with an array of novel marker genes were identified and confirmed by in situ RNA hybridization, and pseudotime analysis of some specific cell types revealed their potential differentiation trajectories. Prominent changes in cell numbers under salt stress were observed for outer epidermal and inner endodermal cells, which were significantly enriched in response to stress, amide biosynthetic process, glutathione metabolism, and glycolysis/gluconeogenesis. Analysis of differentially expressed genes identified in multiple comparisons revealed other functional aggregations concentrated on plant-type primary cell wall biogenesis, defense response, phenylpropanoid biosynthesis, and metabolic pathways. Some candidate differentially expressed genes encoding transcription factors or associated with plant hormones also responsive to salt stress were identified, and the function of Ga03G2153, annotated as auxin-responsive GH3.6, was confirmed by virus-induced gene silencing. The GaGH3.6-silenced plants showed a severe stress-susceptible phenotype, and physiological and biochemical measurements indicated that they suffered more significant oxidative damage. These results suggest that GaGH3.6 might participate in cotton salt tolerance by regulating redox processes. We thus construct a transcriptional atlas of salt-stressed cotton roots at single-cell resolution, enabling us to explore cellular heterogeneity and differentiation trajectories and providing valuable insights into the molecular mechanisms that underlie plant stress tolerance.

The dual role of GoPGF reveals that the pigment glands are synthetic sites of gossypol in aerial parts of cotton.

Gossypol and the related terpenoids are stored in the pigment gland to protect cotton plants from biotic stresses, but little is known about the synthetic sites of these metabolites. Here, we showed that GoPGF, a key gene regulating gland formation, was expressed in gland cells and roots. The chromatin immunoprecipitation sequencing (ChIP-seq) analysis demonstrated that GoPGF targets GhJUB1 to regulate gland morphogenesis. RNA-sequencing (RNA-seq) showed high accumulation of gossypol biosynthetic genes in gland cells. Moreover, integrated analysis of the ChIP-seq and RNA-seq data revealed that GoPGF binds to the promoter of several gossypol biosynthetic genes. The cotton callus overexpressing GoPGF had dramatically increased the gossypol levels, indicating that GoPGF can directly activate the biosynthesis of gossypol. In addition, the gopgf mutant analysis revealed the existence of both GoPGF-dependent and -independent regulation of gossypol production in cotton roots. Our study revealed that the pigment glands are synthetic sites of gossypol in aerial parts of cotton and that GoPGF plays a dual role in regulating gland morphogenesis and gossypol biosynthesis. The study provides new insights for exploring the complex relationship between glands and the metabolites they store in cotton and other plant species.

C-terminally encoded peptides act as signals to increase cotton root nitrate uptake under nonuniform salinity.

Soil salinity is often heterogeneous in saline fields. Nonuniform root salinity increases nitrate uptake into cotton (Gossypium hirsutum) root portions exposed to low salinity, which may be regulated by root portions exposed to high salinity through a systemic long-distance signaling mechanism. However, the signals transmitted between shoots and roots and their precise molecular mechanisms for regulating nitrate uptake remain unknown. Here, we showed that nonuniform root salinity treatment using split-root systems increases the expression of C-TERMINALLY ENCODED PEPTIDE (GhCEP) genes in high-saline-treated root portions. GhCEP peptides originating in high-saline-treated root portions act as ascending long-distance mobile signals transported to the shoots to promote the expression of CEP DOWNSTREAM (GhCEPD) genes by inducing the expression of CEP receptor (GhCEPR) genes. The shoot-derived GhCEPD polypeptides act as descending mobile signals transported to the roots through the phloem, increasing the expression of nitrate transport genes NITRATE TRANSPORTER 1.1 (GhNRT1.1), GhNRT2.1, and GhNRT1.5 in nonsaline-treated root portions, thereby increasing nitrate uptake in the nonsaline-treated root portions. This study indicates that GhCEP and GhCEPD signals are transported between roots and shoots to increase nitrate uptake in cotton, and the transport from the nonsaline root side is in response to nonuniform root salinity distribution.

Progressive drought alters the root exudate metabolome and differentially activates metabolic pathways in cotton (Gossypium hirsutum).

Root exudates comprise various primary and secondary metabolites that are responsive to plant stressors, including drought. As increasing drought episodes are predicted with climate change, identifying shifts in the metabolome profile of drought-induced root exudation is necessary to understand the molecular interactions that govern the relationships between plants, microbiomes, and the environment, which will ultimately aid in developing strategies for sustainable agriculture management. This study utilized an aeroponic system to simulate progressive drought and recovery while non-destructively collecting cotton (Gossypium hirsutum) root exudates. The molecular composition of the collected root exudates was characterized by untargeted metabolomics using Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) and mapped to the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Over 700 unique drought-induced metabolites were identified throughout the water-deficit phase. Potential KEGG pathways and KEGG modules associated with the biosynthesis of flavonoid compounds, plant hormones (abscisic acid and jasmonic acid), and other secondary metabolites were highly induced under severe drought, but not at the wilting point. Additionally, the associated precursors of these metabolites, such as amino acids (phenylalanine and tyrosine), phenylpropanoids, and carotenoids, were also mapped. The potential biochemical transformations were further calculated using the data generated by FT-ICR MS. Under severe drought stress, the highest number of potential biochemical transformations, including methylation, ethyl addition, and oxidation/hydroxylation, were identified, many of which are known reactions in some of the mapped pathways. With the application of FT-ICR MS, we revealed the dynamics of drought-induced secondary metabolites in root exudates in response to drought, providing valuable information for drought-tolerance strategies in cotton.

Comparative analysis of metabolic mechanisms in the remediation of Cd-polluted alkaline soil in cotton field by biochar and biofertilizer

To screen environmentally friendly and efficient Cd pollution remediation material, the effects of BC and BF on soil Cd bio-availability and cotton Cd absorption were analyzed under Cd exposure. Besides, the differences in metabolic mechanisms by which biochar (BC) and biofertilizer (BF) affect Cd-contaminated soil and cotton were also analyzed. The results showed that the application of BC and BF increased cotton dry matter accumulation, boll number, and single boll weight, and reduced the Cd content in cotton roots, stems, leaves, and bolls. At harvest, the Cd content in cotton roots in the BC and BF groups reduced by 15.23% and 16.33%, respectively, compared with that in the control. This was attributed to the conversion of carbonate-bound Cd (carbon-Cd) and exchangeable Cd (EX-Cd) by BC and BF into residual Cd (Res-Cd). It should be noted that the soil available Cd (Ava-Cd) content in the BF group was lower than that in the BC group. The metabolomic analysis results showed that for BC vs BF, the relative abundance of differential metabolites Caffeic acid, Xanthurenic acid, and Shikimic acid in soil and cotton roots were up-regulated. Mantel test found that cotton root exudate l-Histinine was correlated with the enrichment of Cd in various organs of cotton. Therefore, the application of BC and BF can alleviate Cd stress by reducing soil Ava-Cd content and cotton's Cd uptake, and BF is superior to BC in reducing Cd content in soil and cotton organs. This study will provide a reference for the development of efficient techniques for the remediation of Cd-polluted alkaline soil, and provide a basis for subsequent metagenomics analysis.

Continuous wheat-cotton residue incorporation combined with potassium fertilizer improved cotton root production capacity and constructed an optimized photosynthate distribution structure for high seedcotton yield

ABSTRACT In order to strengthen the cognition on synergy between crop residue incorporation and K, a continuous positioning experiment was carried out in 2020 and 2021. Four crop residue incorporation (CK, residue removal, WR, CR, and WR+CR, denoted wheat, cotton, and wheat and cotton residue incorporation) and three K rates (0, 150, and 225 kg K2O ha−1, denoted as K0, K150, and K225, respectively) were set. Compared with CK-K0, WR+CR-K150 increased seed cotton yield by 30.2% which reached the yield level of CK-K225. Taking the maximum theoretical seed cotton yield under CK as target yield, WR+CR, WR, and CR could achieve the same yield level with 59%–62%, 41%–49%, and 35%–43% less K fertilizer, respectively. Higher load capacity of root (LCR), boll loading of root (BLR) and lower root–shoot ratio (R/S) were observed at the boll-opening stage under the combined condition. When R/S, LCR and BLR were 0.12 g g−1, 4.00 g g−1 and 1.12 boll g−1, cotton could achieve maximum theoretical yield. 13C labeling result showed that WR+CR-K150 increased reproductive organ distribution proportion by 30.5% on average as compared with CK-K0. Thus, WR+CR-K150 can increase seed cotton yield by improving cotton root production capacity and increasing the photosynthate distribution proportion in reproductive organ.

Survey, Incidence and Pathogenicity of Root Rot Disease of Cotton in Different Districts of Haryana Incited by Rhizoctonia spp

Aim: Survey, incidence and pathogenicity of root rot disease of cotton in different districts of Haryana incited by Rhizoctonia spp.
 Design: Survey.
 Place and Duration of Study: Ten major cotton growing districts in Haryana during Kharif 2021 and Kharif 2022.
 Methodology: A roving survey to record cotton root rot incidence was conducted in ten major cotton growing districts of Haryana during the month of June and July for consecutive two Kharif seasons 2021 and 2022. On an average 4 growing region of cotton in each district were visited and percent disease incidence was recorded.
 Results: Among all the surveyed districts of Haryana the maximum mean disease incidence was recorded in Fatehabad (18.75%) followed by Hisar (15.25 %), Sirsa (15%), While the minimum disease incidence was recorded in Nuh and Charkhi dadri 9.25 per cent in both during kharif 2021. Among all the surveyed districts of Haryana the maximum mean disease incidence was recorded in Fatehabad (18.25%) followed by Sirsa (15.25%), Hisar (15.42%), While the minimum disease incidence was recorded Charkhi dadri (9.08%).
 Conclusion: The results of the current study showed that important cotton-growing regions in Haryana have root rot disease incidence. It is clear from the overall study that root rot disease is common in significant mulberry-growing regions in Haryana. As a result, resistant cotton types are urgently needed to address the grower's issue, together with the best management techniques, such as effective biocontrol agents that can significantly reduce the illness. Consequently, research should be conducted to ascertain the incidence of the disease in different places.

Enhancement patterns of potassium on nitrogen transport and functional genes in cotton vary with nitrogen levels

The application of potassium (K) in conjunction with nitrogen (N) has been shown to enhance N use efficiency. However, there is still a need for further understanding of the optimal ratios and molecular regulatory mechanisms, particularly in soil-cotton systems. Here, a field trial was conducted, involving varying rates of N and K, alongside pot and hydroponic experiments. The objective was to assess the impact of N-K interaction on the absorption, transport and distribution of N in cotton. The results showed that K supply at 90 and 240 kg ha−1 had a beneficial impact on N uptake and distribution to both seed and lint, resulting in the highest N use efficiency ranging from 22% to 62% and yield improvements from 20% to 123%. The increase in stem and root diameters, rather than the quantify of xylem vessels and phloem sieve tubes, facilitated the uptake and transport of N due to the provision of K. At the molecular level, K supply upregulated the expression levels of genes encoding GhNRT2.1 transporter and GhSLAH3 channel in cotton roots to promote N uptake and GhNRT1.5/NPF7.3 genes to transport N to shoot under low-N conditions. However, under high-N conditions, K supply induced anion channel genes (GhSLAH4) of roots to promote N uptake and genes encoding GhNRT1.5/NPF7.3 and GhNRT1.8/NPF7.2 transporters to facilitate NO3- unloading from xylem to mesophyll cell in high-N plants. Furthermore, K supply resulted in the upregulation of gene expression for GhGS2 in leaves, while simultaneously downregulating the expression of GhNADH-GOGAT, GhGDH1 and GhGDH3 genes in high-N roots. The enzyme activities of nitrite reductase and glutamine synthetase increased and glutamate dehydrogenase decreased, but the concentration of NO3- and soluble protein exhibited a significant increase and free amino acid decreased in the shoots subsequent to K supply.

Reduced tillage and subsurface fertigation improve productivity and economic benefits in the cotton-wheat cropping system

Soil compaction under repetitive tillage and surface flood method of irrigation (SFMI) are significant hurdles for sustaining crop production in India, necessitating the adoption of efficient soil and water management strategies. Hence, a 3-year field study was conducted at two diverse agro-climatic locations (Abohar and Faridkot) to investigate the impact of subsurface drip (SUSD) fertigation on crop and water productivity of cotton-wheat cropping system (CWCS), over traditional practice (TP) (conventional tillage with SFMI and manual application of nutrients). The experiment was conducted in a factorial randomized complete block design with three levels of subsurface drip irrigation (SUSDI) [100, 80, and 60% of crop evapotranspiration (ETc)] and two fertigation levels [75% recommended dose of nutrients (RDN) and 100% RDN], where TP and surface drip (SD) fertigation at 80% ETc coupled with 100% RDN (Control 2), served as two control treatments. Cotton was raised through reduced tillage, while zero till drill was used for sowing wheat. The results revealed that, barring SUSDI at 60% ETc, both crops exhibited improved yield under all drip combinations of reduced or zero tillage over TP. Better mass and higher length of cotton roots in drip fertigation were evident due to improved steady-state infiltration rates (SSIR) and reduced bulk density (BD) under conservation tillage. When 100% RDN was applied, the 100% and 80% ETc SUSDI resulted in 26.7% and 24.7% higher seed cotton yield (SCY) than TP. Similarly, wheat yield with 100% RDN was improved by 10.5% and 14.4% under SUSDI of 80% and 100% ETc, respectively, over the TP. The results indicated that SUSD can be clubbed with reduced tillage for better soil health, improved crop yield, and higher apparent water productivity. The improved benefit to cost (B:C) owing to enhanced monetary returns over TP also substantiated that reduced tillage with SUSD is a viable and remunerative practice for CWCS. The study elucidated that reduced tillage exercised a beneficial effect on physical soil properties by lowering BD and improving SSIR. At the same time, SUSD could save huge amounts of irrigation water besides enhanced input use efficiency leading to higher crop productivity.

Research results on underground cotton irrigation through artificial pipes

The article presents the results of laboratory-field tests of a working body that creates an artificial pipe for irrigation of cotton with a row spacing of 60 cm from under the soil. As evaluation criteria, water flow distance and moisture dispersion were taken from inside the formed pipe without spilling onto the field surface. When using this working body, it was found that a pipe with dense walls was formed under the soil with low energy consumption, and water flow was observed for a long distance. Generated to the proximity of the constructed artificial pipes to the cotton roots, the water demand is met quickly and the irrigation time and water consumption are reduced.