Effects Of Water Deficit Research Articles

Effects of water deficit on two cultivars of Hibiscus mutabilis: A comprehensive study on morphological, physiological, and metabolic responses

Hibiscus mutabilis, commonly known as the cotton rose, is a widely cultivated ornamental and has been acclaimed as the representative flower of the 2024 World Horticultural Exposition. The growth and ornamental characteristics of Hibiscus mutabilis can be affected by drought stress. Therefore, we investigated the physiological and metabolic responses of drought-sensitive Hibiscus mutabilis JRX-1 and drought-tolerant Hibiscus mutabilis CDS-4 under drought stress. The results of the physiological analyses revealed that, compared to JRX-1,CDS-4 maintained good growth and greater water use efficiency through stronger antioxidant defences, osmoregulatory capacity and stomatal regulation . A total of 3277 metabolites were identified in positive and negative ion modes, of which 663 metabolites presented changes in expression under drought conditions, including 306 upregulated metabolites and 357 downregulated metabolites. Secondary metabolites, such as flavonoids and diterpenoids , are crucial in the plant response to drought stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the differentially aboundant metabolites were significantly enriched in the pathways valine, leucine and isoleucine degradation; linoleic acid metabolism; one carbon pool by folate; and folate biosynthesis. The results of this study will not only help to elucidate and apply the physiological and metabolic regulatory strategies of Hibiscus mutabilis to improve its adaptation to water deficit conditions, but will also provide valuable guidance to breeders and molecular biologists in the screening and use of drought resistant genes in ornamental plants.

Studying the Combined Impact of Salinity and Drought Stress-Simulated Conditions on Physio-Biochemical Characteristics of Lettuce Plant

Water scarcity and increasing salinity stress are significant challenges in the farming sector as they often exacerbate each other, as limited water availability can concentrate salts in the soil, further hindering plant growth. Lettuce, a crucial leafy vegetable with high nutritional value, is susceptible to water availability and quality. This study investigates the growth and development of lettuce plants under water scarcity and varying levels of salinity stress to identify effective strategies for reducing water consumption while maintaining or improving plant productivity. Field experiments were designed to simulate three drought levels (50, 75, and 100% of class A pan evaporation) and three salinity stress levels (control, 1500, and 3000 ppm NaCl), assessing their impact on lettuce’s morphological and biochemical parameters. The combination of reduced water supply and high salinity significantly hindered growth, underscoring the detrimental effects of simultaneous water deficit and salinity stress on plant development. Non-stressed treatment enhanced nitrogen, phosphorus, and potassium contents and progressively decreased with the reduction in water supply from 100% to 50%. Interestingly, higher salinity levels increased total phenolic, flavonoid, and antioxidant activity, suggesting an adaptive stress response. Moreover, antioxidant activity, evaluated through DPPH and ABTS assays, peaked in plants irrigated with 75% ETo, whether under control or 1500 ppm salinity conditions. The Yield Stability Index was highest at 75% ETo (0.95), indicating robust stability under stress. The results indicated that lettuce could be cultivated with up to 75% of the water requirement without significantly impacting plant development or quality. Furthermore, the investigation demonstrated that lettuce could thrive when irrigated with water of moderate salinity (1500 ppm). These findings highlight the potential for reducing water quantities and saline water in lettuce production, offering practical solutions for sustainable farming in water-scarce regions.

Exploring the response of yellow lupine (Lupinus luteus L.) root to drought mediated by pathways related to phytohormones, lipid, and redox homeostasis.

Yellow lupine (Lupinus luteus L.) is a high-protein crop of considerable economic and ecological significance. It has the ability to fix atmospheric nitrogen in symbiosis with Rhizobium, enriching marginal soils with this essential nutrient and reducing the need for artificial fertilizers. Additionally, lupine produces seeds with a high protein content, making it valuable for animal feed production. However, drought negatively affects lupine development, its mutualistic relationship with bacteria, and overall yield. To understand how lupine responds to this stress, global transcriptome sequencing was conducted, along with in-depth biochemical, chromatography, and microscopy analyses of roots subjected to drought. The results presented here contribute to strategies aimed at mitigating the effects of water deficit on lupine growth and development. Based on RNA-seq, drought-specific genes were identified and annotated to biological pathways involved in phytohormone biosynthesis/signaling, lipid metabolism, and redox homeostasis. Our findings indicate that drought-induced disruption of redox balance characterized by the upregulation of reactive oxygen species (ROS) scavenging enzymes, coincided with the accumulation of lipid-metabolizing enzymes, such as phospholipase D (PLD) and lipoxygenase (LOX). This disruption also led to modifications in lipid homeostasis, including increased levels of triacylglycerols (TAG) and free fatty acids (FFA), along with a decrease in polar lipid content. Additionally, the stress response involved alterations in the transcriptional regulation of the linolenic acid metabolism network, resulting in changes in the composition of fatty acids containing 18 carbons. The first comprehensive global transcriptomic profiles of lupine roots, combined with the identification of key stress-responsive molecules, represent a significant advancement in understanding lupine's responses to abiotic stress. The increased expression of the Δ12DESATURASE gene and enhanced PLD activity lead to higher level of linoleic acid (18:2), which is subsequently oxidized by LOX, resulting in membrane damage and malondialdehyde (MDA) accumulation. Oxidative stress elevates the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), while the conversion of FFAs into TAGs provides protection against ROS. This research offers valuable molecular and biochemical candidates with significant potential to enhance drought tolerance . It enables innovative strategies in lupine breeding and crop improvement to address critical agricultural challenges.

Production and postharvest quality of sour passion fruit under deficit irrigation strategies and foliar application of ascorbic acid

ABSTRACT The objective this study was to evaluate the effects of foliar application of ascorbic acid – AsA on the production and postharvest quality of sour passion fruit under deficit irrigation strategies. The experimental design was randomised blocks, in a split-plot scheme, with plots consisting of six strategies of irrigation with water deficit, based on crop evapotranspiration – ETc (irrigation with 100% ETc during the entire cycle – S1; irrigation with 50% ETc in the different stages: vegetative – S2; flowering – S3; fruiting – S4; and successively in the vegetative/flowering stages – S5; and vegetative/fruiting stages – S6) and three concentrations of AsA (0, 88.06 and 176.12 mg/L), with three replicates and three plants per plot. Water deficit reduces the production of sour passion fruit, regardless of the phenological stage of the plants without AsA application. Irrigation with water deficit in the flowering stage (50% of crop evapotranspiration) reduces the physical and chemical quality of sour passion fruits. Ascorbic acid in applied levels was effective in alleviating the effects of water deficit on production, with emphasis on the concentration of 176.12 mg/L on the quality of sour passion fruits, in the period from 160 to 220 days after transplanting.

Alteration in certain growth, biochemical, and anatomical indices of grapevine (Vitis vinifera) in response to the foliar application of auxin under water deficit.

Drought-induced stress represents one of the most economically detrimental natural phenomena impacting grapevine (Vitis vinifera ) development, yield, and fruit characteristics. Also, auxin is one of the most important plant growth regulators that can reduce damage caused by stress in plants. In this study, the impact of exogenously sprayed auxin (0, 50, and 200mgL-1 ) on growth, biochemical, and anatomical parameters was investigated in two grapevine varieties (cvs. 'Rashe' and 'Fakhri') under water deficit. According to our findings, water deficit led to a notable decrease in growth, protein content, and anatomical parameters; but significantly enhanced electrolyte leakage. Grapevines exposed to water deficit exhibited substantial increases in total phenolic compounds and antioxidant activity. Applying 50mgL-1 napthalene acetic acid (NAA) reduced the effects of water deficit in both grapevine cultivars by decreasing electrolyte leakage (15% in 'Rashe' and 20% in 'Fakhri'), and accumulating protein content (22% 'Rashe' and 32% 'Fakhri'), total phenolic compounds (33%'Rashe' and 40% 'Fakhri'), and antioxidant capacity (11% 'Rashe' and 39% 'Fakhri'); anantomical parameters were also improved. However, application of 200mgL-1 NAA had adverse effects on growth and biochemical traits of grapevines, with a more pronounced impact on root growth and anatomical parameters compared to other NAA concentrations. In conclusion, the application of 50mgL-1 NAA enhanced grapevine growth, enabling them to better thrive under water deficit.

Water deficit and aphid resilience on wheat: examining Sitobion avenae F. and their bacterial symbionts interplay under controlled laboratory conditions.

Climate change has far-reaching effects on food security and agriculture, affecting crop yields and food distribution. Agriculture relies heavily on water for irrigation and production, making it vulnerable to water scarcity. Additionally, climate change can affect crop pest insects, leading to increased global crop losses, particularly in cereals, an important component of the human diet. Aphids are major crop pests and have a symbiotic relationship with bacterial endosymbionts that can contribute to their success as pests under a climate change scenario. To test the effect of drought on aphids, we examined varying levels of water deficit and endosymbiont composition on the grain aphid (Sitobion avenae) performance on wheat under controlled laboratory conditions. We measured the intrinsic rate of population increase (rm), the body weight of adult aphids, and the pre-reproductive period for different genotypes of the grain aphid (including Chilean superclones) under different irrigation regimes. We also analyzed the relative abundance of their endosymbionts under the different water treatments. Our findings revealed that water deficit affects each aphid genotype differently, impacting various traits. For instance, the body weight of adult aphids was notably affected by different water treatments, with aphids grown under intermediate water deficit (IW) being significantly bigger. The relative abundance of endosymbionts also varied among genotypes and water treatments-specifically Regiella insecticola had a noticeably higher abundance under IW (P < 0.05). This study provides valuable insights into the impact of water deficit on aphid performance and the role of endosymbionts in mitigating the effects of water deficit. © 2024 Society of Chemical Industry.

The Influence of Water Deficit on Dehydrin Content in Callus Culture Cells of Scots Pine

Under a water deficit, the protective proteins known as dehydrins (DHNs) prevent nonspecific interactions in protein and membrane structures and their damage, in addition to playing an antioxidant role. The DHNs of a widespread xerophytic species Scots pine (Pinus sylvestris L.) have been poorly studied, and their role in resistance to water deficits has not been revealed. In this paper, we have expanded the list of DHNs that accumulate in the cells of Scots pine under the conditions of water deficits and revealed their relationship with the effects of water deficits. In this investigation, callus cultures of branches and buds of Scots pine were used. A weak water deficit was created by adding polyethylene glycol to the culture medium. Under the conditions of a water deficit, the activity of catalase and peroxidase enzymes increased in the callus cultures. A moderate decrease in the total water content was correlated with a decrease in the growth rate of the callus cultures, as well as with an increase in the activity of lipid peroxidation. The accumulation of Mr 72, 38, and 27 kDa DHNs occurred in the callus cultures of buds, and the accumulation of Mr 72 and 27 kDa DHNs positively correlated with the lipid peroxidation activity. An increase in the content of DHNs was observed in cultures that differed in origin, growth indicators, and biochemical parameters, indicating the universality of this reaction. Thus, previously undescribed DHNs were identified, the accumulation of which is caused by water deficiency and is associated with manifestations of oxidative stress in the kidney cells of Scots pine.

A Moderate Water Deficit Induces Profound Changes in the Proteome of Developing Maize Ovaries.

Water deficit is a major cause of yield loss for maize (Zea mays), leading to ovary abortion when applied at flowering time. To help understand the mechanisms involved in this phenomenon, the proteome response to water deficit has been analysed in developing ovaries at the silk emergence stage and five days later. Differential analysis, abundance pattern clustering and co-expression networks were performed in order to draw a general picture of the proteome changes all along ovary development and under the effect of water deficit. The results show that even mild water deficit has a major impact on ovary proteome, but this impact is very different from a response to stress. A part of the changes can be related to a slowdown of ovary development, while another part cannot. In particular, ovaries submitted to water deficit show an increase in proteins involved in protein biosynthesis and in vesicle transport together with a decrease in proteins involved in amino acid metabolism and proteolysis. According to the functions of increased proteins, the changes may be linked to auxin, brassinosteroids and jasmonate signalling but not abscisic acid.

Effect of Water Deficit on Secondary Metabolites and Nutrient Content on Forage Sorghum

Agronomic properties are more likely to be impacted by water deficits that affect the nutrient uptake and production of secondary metabolites based on their timing and intensity. The aim of this study was to assess the effects of the water deficit on the nutritional quality of forage sorghum (Sorghum bicolor) hybrids. For that purpose, a factorial, completely randomized experiment was conducted by considering three forage sorghum hybrids (AGRI 002-E, BREVANT SS318, and BRS 658) and two levels of evapotranspiration water replacement (50% and 100% of ETc). Parameters relating to water consumption, secondary metabolites (isoflavones daidzein, daidzin, genistein, and genistin), leaf nutrients (P, K, Ca, Mg, S, Mn, and Zn), and bromatological attributes (dry matter, crude protein, neutral detergent fiber, and mineral material) were evaluated at the end of the crop cycle. Isoflavone levels differed between the hybrids and were highest in water-deficient sorghum. There was a significant interaction between the factors only for the daidzin. The leaf content of the other compounds was influenced either by hybrids (genistein) or by the replacement of evapotranspired water levels (daidzein). The leaf content of P and S was influenced by the interaction between the factors, while the levels of K, Ca, and Mg were influenced by the effect of a single factor. The leaf contents of Mn and Zn were not influenced by the treatments. There was a difference between the hybrids for dry mass and crude protein contents, and hybrids x water deficit was only significant for dry mass. The hybrids Brevant SS318 and BRS 658 had the highest crude protein. The presented results are novel and demonstrate that water deficits can significantly affect the levels of secondary metabolites and the nutritional quality of forage sorghum, depending on the hybrid. The mentioned indices are important parameters for evaluating the nutritional quality and development of agricultural crops, particularly in response to adverse environmental conditions such as water stress.

Interactive effects of water deficit and nitrogen deficiency on photosynthesis, its underlying component processes, and carbon loss processes in cotton

AbstractDrought stress and nitrogen (N) deficiency are important abiotic stresses that severely limit net photosynthetic rate (AN). A number of studies have investigated the underlying physiological limitations to AN in response to water deficit or N deficiency; however, the relative sensitivities of photosynthetic component processes and carbon loss processes to combined drought and N deficiency in field‐grown cotton (Gossypium hirsutum L.) have not been explored. Therefore, the objective of the present study was to determine the effects of combined water deficit and nitrogen deficiency on the underlying physiological processes driving AN in field‐grown cotton. Water‐deficit stress caused substantial reductions in AN, but reductions in AN were greater under optimum N conditions (74%) than under N deficiency (22%). Decreased CO2 diffusion, RuBP regeneration, and Rubisco carboxylation were major contributors to a decline in AN due to water‐deficit stress. Reductions in Rubisco carboxylation and RuBP regeneration were the greatest drivers of N deficiency‐induced decline in AN. Lower CO2 diffusion and Rubisco carboxylation were main constraints to AN due to combined water deficit and N deficiency. Regarding carbon loss processes, both dark respiration and photorespiration under water‐deficit stress or N deficiency, and only photorespiration under combined water deficit and N deficiency, contributed to declines in AN. Increased non‐photochemical quenching and/or photorespiration prevented photoinhibition of photosystem II under stress conditions. Overall, response of photosynthesis to water‐deficit stress was dependent on N availability, and rate‐limiting physiological processes contributing to declines in AN were dependent on the type of prevailing stress.

Effect of different timing of water deficit combined with foliar application of ascorbic acid on physiological variables of sour passion fruit

The objective of this study was to evaluate the effects of deficit irrigation treatments during different phenological stages and foliar application of ascorbic acid on gas exchange, photosynthetic pigments, chlorophyll fluorescence, electrolyte leakage, relative water content and yield of ‘BRS GA1’ sour passion fruit. Treatments were distributed in randomized blocks, in a split-plot scheme, with plots consisting of six deficit irrigation treatments, based on crop evapotranspiration – ETc (irrigation with 100% ETc - FULL; irrigation with 50% ETc in the vegetative stage - VEG; flowering stage - FLO; fruiting stage - FRU; successively in the vegetative/flowering stages - VEG + FLO and vegetative/fruiting stages - VEG + FRU) and subplots represented by three concentrations of ascorbic acid - AsA (0, 0.5 and 1.0 mM). Water deficit induces changes in photosynthetic activity across all developmental stages of sour passion fruit, resulting in reduced yield in the period of 160 and 200 days after transplanting. Notably, flowering exhibits the greatest physiological acclimatization to water deficit conditions, albeit with more pronounced losses in the yield. When water deficit occurs during the vegetative and fruiting stages and is coupled with foliar application of ascorbic acid at 0.5 mM, there is an enhancement in the synthesis of photosynthetic pigments in ‘BRS GA1’ sour passion fruit. Overall, foliar application of ascorbic acid at concentrations of 0.5 and 1.0 mM emerges as a viable strategy to mitigate the adverse effects of water deficit on the physiology and yield of sour passion fruit at 200 days after transplanting.

Epichloë endophytes can alleviate water deficit effects on perennial ryegrass through host morpho-physiological modulation

Water deficit stress largely limits plant growth and survival in natural and managed ecosystems. We studied the morpho-physiological responses of plants associated with distinct strains of Epichloë fungal endophytes to water deficit. We hypothesised that Epichloë symbionts would alleviate the negative effects of water deficit on plants and that both magnitude and mechanisms of endophyte-based alleviation would vary depending on the Epichloë strain. Perennial ryegrass (Lolium perenne) plants from the experimental cultivar GA66 associated with the Epichloë strains AR1, AR5, AR6, and AR37 were subjected to a treatment of sustained water deficit in a pot experiment under controlled growth conditions. We measured plant biomass (shoot and root), water retention, stress-related phytohormones (abscisic acid, jasmonic acid), proline and other water-soluble amino acids, and Epichloë-derived antiherbivore alkaloids. Alleviation of the negative effects of water deficit on plants depended on the Epichloë strain, with AR37 and AR5 providing the greatest protection followed by AR1, while AR6 did not alleviate stress. The AR37-derived water deficit alleviation was associated with enhanced root biomass and plant water retention, and increased concentrations of abscisic acid, proline, and fungal alkaloids. The AR5-derived stress alleviation was associated with enhanced plant water retention and increased proline concentrations, and the AR1-derived alleviation with increased fungal alkaloid concentrations and mycelial biomass. Although AR6 did not alleviate the water deficit, the stress increased Epichloë-derived alkaloid concentrations (and enhanced root biomass) which could provide an advantage for resisting herbivory. Our study highlighted that while Epichloë generally alleviated the effects of water deficit on plants, the mechanisms of stress alleviation varied among associations, and that the host fitness could be increased even in those associations where endophytes did not alleviate direct water deficit stress if herbivores would be present.

Protective Role of Polyethylene Glycol Towards the Damaging Effects of Cadmium.

This study aimed to evaluate the role of drought-induced changes in the effects of cadmium (Cd) in plants. Cd is the most hazardous and important environmental pollutant. Water deficit is the most common environmental stress encountered by plants and affects most of the plant functions. The present study assessed the effect of Cd and water deficit on Capsicum frutescens seedlings in single and combined treatments. The seedlings of Capsicum were grown in a hydroponic solution and treated with Cd. The seedlings were subjected to water deficit with the help of polyethylene glycol (PEG). The other set of seedlings was treated with combined Cd + PEG. In the absence of PEG, maximum Cd accumulation was observed. The root and shoot growth of the seedlings were affected under all treatments with maximum inhibition in Cd. Pigment, protein and sugar contents and nitrate reductase activity decreased significantly in all treatments, while proline content increased. Induction of oxidative damage occurred through the formation of free radicals which caused alteration in electrolyte leakage, lipid peroxidation and activities of antioxidant enzymes, viz. superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase and non-enzymatic non-protein thiol content and ascorbic acid in the stressed seedlings. Water deficit buttressed the toxic effect of Cd on chilli seedlings.

Photosynthetic Limitations and Growth Traits of Four Arabica Coffee (Coffea arabica L.) Genotypes under Water Deficit

Climate change increases the risk of coffee yield due to the genotype-dependent effects of water deficit on coffee physiology. The goal of this research was to evaluate how water deficit altered the physiological and growth characteristics of arabica coffee (Coffea arabica L.). Water status, photosynthetic response to CO2 intercellular concentration (A/Ci curves) and growth parameters were evaluated in seedlings of four genotypes (Catimor ECU 02, Cavimor ECU, red Caturra and Sarchimor 4260). Most of the physiological traits evaluated differed significantly among genotypes. Between control and water deficit plants, significant variations occurred in the A/Ci parameters, showing a wide range of values for net photosynthetic rate, stomatal conductance, and water use efficiency, with decreases ranging from 4 to 74%. Maximum electron transport rate through photosystem II, highest rate of RuBisCO carboxylation, and triose phosphate utilization rate were all strongly decreased by water deficit 61% (red Caturra and Sarchimor 4260), followed by Cavimor ECU (35%) and Catimor ECU 02 (24%). Differences in response to water deficit among genotypes suggest possible genotypic differences in tolerance. The results indicated that Catimor ECU 02 and Cavimor ECU were less sensitive to water deficit, while red Caturra and Sarchimor 4260 were the most susceptible.

Water deficit affects the nitrogen nutrition index of winter wheat under controlled water conditions

Nitrogen (N) uptake is regulated by water availability, and a water deficit can limit crop N responses by reducing N uptake and utilization. The complex and multifaceted interplay between water availability and the crop N response makes it difficult to predict and quantify the effect of water deficit on crop N status. The nitrogen nutrition index (NNI) has been widely used to accurately diagnose crop N status and to evaluate the effectiveness of N application. The decline of NNI under water-limiting conditions has been documented, although the underlying mechanism governing this decline is not fully understood. This study aimed to elucidate the reason for the decline of NNI under water-limiting conditions and to provide insights into the accurate utilization of NNI for assessing crop N status under different water-N interaction treatments. Rainout shelter experiments were conducted over three growing seasons from 2018 to 2021 under different N (75 and 225 kg N ha-1, low N and high N) and water (120 to 510 mm, W0 to W3) co-limitation treatments. Plant N accumulation, shoot biomass (SB), plant N concentration (%N), soil nitrate-N content, actual evapotranspiration (ETa), and yield were recorded at the stem elongation, booting, anthesis and grain filling stages. Compared to W0, the W1 to W3 treatments exhibited NNI values that were greater by 10.2 to 20.5%, 12.6 to 24.8%, 14 to 24.8%, and 16.8 to 24.8% at stem elongation, booting, anthesis, and grain filling, respectively, across the 2018-2021 seasons. This decline in NNI under water-limiting conditions stemmed from two main factors. First, reduced ETa and SB led to a greater critical N concentration (%Nc) under water-limiting conditions, which contributed to the decline in NNI primarily under high N conditions. Second, changes in plant %N played a more significant role under low N conditions. Plant N accumulation exhibited a positive allometric relationship with SB and a negative relationship with soil nitrate-N content under water-limiting conditions, indicating co-regulation by SB and the soil nitrate-N content. However, this regulation was influenced by water availability. Plant N accumulation sourced from the soil nitrate-N content reflects soil N availability. Greater soil water availability facilitated greater absorption of soil nitrate-N into the plants, leading to a positive correlation between plant N accumulation and ETa across the different water-N interaction treatments. Therefore, considering the impact of soil water availability is crucial when assessing soil N availability under water-limiting conditions. The findings of this study provide valuable insights into the factors contributing to the decline in NNI among different water-N interaction treatments and can contribute to the more accurate utilization of NNI for assessing winter wheat N status.

Comprehensive analysis on investigating water-saving potentials of irrigated cotton in semi-arid area in China

Deficit irrigation is a common strategy to reduce water use and improve the sustainability of cotton production. However, the effects of water deficits on crop productivity and quality are subject to genotype by management by environmental interactions. This study investigated effects of water deficits and frequency of irrigation on cotton performance grown in semi-arid region, Xinjiang, the main cotton-growing area in China. Two field trials (2020 and 2021) with split experimental design, including main factors of three irrigation levels (moderate-deficit, mild-deficit and full-irrigation) and split factors of three irrigation frequencies (4, 8 and 12 days) were conducted. Results from two trials both showed little negative influence of irrigation levels on yield, and higher irrigation frequency improved yield under same irrigation level. Significant effects of irrigation levels on yield components were found in 2021, with a 22 % increase in boll number and an 18 % reduction in boll weight under moderate-deficit irrigation compared with those under full-irrigation. Interactions between irrigation levels and frequencies significantly affected harvest index (HI), showing that reduced irrigation might be beneficial for improving HI. However, decreased fibre length while increased fibre micronaire were found under deficit irrigation. A strong association between radiation use efficiency (RUE) and boll growth rate was observed, suggesting that RUE might be the driving force of yield formation. A tight correlation between both biomass and transpiration efficiency versus delta temperature between air and canopy (ΔTair-canopy) was observed, suggesting ΔTair-canopy could be used as an efficient tool to assess plant production under deficit irrigation. This study provided an improved understanding of the physiological basis of cotton yield formation and further identified a high-throughput and instantaneous method to monitor effects of deficit irrigation on crop productivity.

Effect of water-deficit on stem reserve mobilization for grain filling in wheat (Triticum aestivum L.)

Effect of water-deficit on stem reserve mobilization for grain filling in wheat (Triticum aestivum L.)

Photosynthetic Acclimation of Larch to the Coupled Effects of Light Intensity and Water Deficit in Regions with Changing Water Availability.

The impact of frequent water deficits on dominant tree species in boreal forests has received increased attention, particularly towards addressing the global climate change scenarios. However, the impacts of coupled light intensity and water deficit in the regeneration and growth of Larix gmelinii seedlings, a dominant species in China's boreal forests, are still unclear. We conducted a dual-factor controlled experiment with four light intensities (natural sunlight, 50% shading, 75% shading, and 90% shading) and three soil water conditions (80%, 60%, and 40% soil saturated water content). The results showed that the coupling of light and water has a significant effect on the growth and development of Larix gmelinii seedlings. In 40% of the saturated soil moisture content, net photosynthetic rate, transpiration rate, chlorophyll a, and total phenol-leaf were significantly lower than the same light conditions under 80% soil saturated water content. Under the coupling treatment of 60% soil saturated water content and 50% shading treatment, the plant height increment, net photosynthetic rate, stomatal conductance, transpiration rate, chlorophyll a, and phenolic compound content were significantly higher than those of other coupling treatments; however, more than 75% shading inhibited photosynthetic parameters, chlorophyll a, total flavonoid-leaf, and total flavonoid-branch. Our results have important implications for forest management practices; they provide a scientific reference for the early growth of Larix gmelinii seedlings under the coupling of light and water and promote the survival and growth of seedlings.

The Cause and Effects of Water Shortage in Ukhrul District, Manipur, India

The Cause and Effects of Water Shortage in Ukhrul District, Manipur, India

Evaluación de parámetros relacionados con el crecimiento de plantas de café (Coffea arabica L.) en respuesta al déficit hídrico del suelo

Contextualization: Water is indispensable for plant development, and its response to water deficit varies according to the species and their growth stages. Knowledge gap: The magnitude of the effect of soil water deficit on the growth of young coffee (Coffea arabica L.) plants evaluated over time is unknown. Purpose: Research was carried out to identify the effect of soil water deficit and, therefore, the sensitivity to drought in young coffee plants. Methodology: The deficit irrigation method was used. Coffee plants of the Cenicafé 1 variety were planted at three months old in cylindrical pots and conditioned for four months in mesh houses at Cenicafé - Planalto. After conditioning, the effect on plants' growth and dry matter subjected to five ranges of soil matric potential was evaluated over 140 days. Potentials ranged from -20±10 kPa (control) to -1600±100 kPa. Results and conclusions: The results showed that soil water deficit affects the growth of young coffee (C. arabica) plants, which could define C. arabica at this stage as drought sensitive. Plants subjected to the least stress and the extreme drought showed a 30% and 57% decrease in dry matter, respectively. For growth variables, the effect of water deficit was evident in the evaluations at 77, 113, and 140 days of treatment application. In all cases, the results showed differences between the extreme drought and the control of up to 30cm in height and equatorial diameter, 0.9 m2 of leaf area, 132 leaves, 3 branches, and 66 nodes. The mathematical models that explained the effect of drought on dry mass were of the logarithmic type. It was identified that for weather and soil conditions similar to those in the study, young coffee plants begin to deteriorate after 40 days of drought. With a soil matric potential close to -40 kPa, for a time of 120 days, coffee plants can lose 10% of dry mass, and when the potential exceeds -90 kPa there can be further losses in dry matter and decreases in the number of branches between the 77 and 113 days.