Reduced Plant Height Research Articles

Positive Effects of Growth Retardants on Castor (Ricinus communis L.)

The perennial growth habit of castor plants (Ricinus communis L.) limits mechanical harvest because the plant grows very tall, when the environmental conditions are favorable and produces green flush interfering with mechanical harvesting. In order to prevent excessive growth plant growth, retardant are applied to modifying crop architecture. Present investigation was designed to study the effect of growth retardants on growth and yield parameters. The experiment was conducted at the regional agricultural research station, Palem farm of Professor Jayashankar Telangana Agricultural University, Nagarkurnool district, Telangana, taking locally available tall variety PCH-111. The experiment was laid out in Randomized Block Design with three replicates in Kharif, 2019. Treatments comprises of water spray, ethrel@500 ppm, ethrel@1000 ppm, CCC@1.5ml/lit, CCC@2.0 ml/lit and CCC@2.5 ml/lit and sprayings were done at expanding leaf in the 6th node of the primary stem, expanding leaf on the 8th node of the primary stem, appearance of the first inflorescence, one expanding leaf in a secondary stem after the appearance of the first inflorescence, and appearance of the second inflorescence. Results revealed that, plant growth retardants are effective in reducing plant height, whereas no spray recorded significant superior value for plant height (70.73 cm). For leaf number, there is no much deviations though ethrel treatment enhanced senescence in older leaves, newly developed leaves compensated the number but there was reduction in LAI, which were 1.70 and 2.18, respectively, in ethrel spray of 1000 ppm and 500 ppm. The yield reduction is lower in ethrel treatment due to lower capsule formation and lower spike length at higher concentration of ethrel. Hence, it is concluded that, retardant accelerates natural senescence and thus, acting as defoliants overcoming difficulties in mechanical harvesting.

Chrysin alleviates salt stress in tomato by physiological, biochemical, and genetic mechanisms

Soil salinity greatly reduces agricultural productivity, especially in dry and semi-arid regions, by interfering with physiological and biochemical processes. This research aimed to determine whether Chrysin (Chr) can mitigate the negative effects of salinity on growth parameters, antioxidant enzyme activity, and gene expression in tomato (Solanum lycopersicum L.) plants. Experiments were conducted in a semi-controlled greenhouse, with plants subjected to varying concentrations of sodium chloride (NaCl) (0 and 100 mM) and Chr (0, 0.1, 0.5, and 1.0 mM). Results revealed that salinity stress significantly reduced plant height, leaf area, and chlorophyll content while increasing hydrogen peroxide (H2O2), malondialdehyde (MDA), and proline levels, indicating oxidative stress. Chr application alleviated these detrimental effects by enhancing the activity of antioxidant enzymes such as catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), thereby reducing reactive oxygen species (ROS) accumulation. Additionally, Chr treatments improved plant water status and mineral content under salt stress. Gene expression analysis showed that Chr positively regulated the transcription of salt tolerance-related genes, including HKT1-1, HKT1-2, and PIP1-2, which are associated with sodium ion transport and water balance. These findings suggest that Chr can be an effective biostimulant for enhancing salt tolerance in tomato plants by modulating physiological, biochemical, and genetic mechanisms. This study provides insights into Chr's potential as a sustainable solution for improving crop resilience to salinity in agricultural practices. Further research is recommended to optimize Chr concentrations for maximum efficacy.

Tomato SlARF5 participate in the flower organ initiation process and control plant height

Plant height is a critical agronomic trait closely linked to yield, primarily regulated by Gibberellins (GA) and auxins, which interact in complex ways. However, the mechanism underlying their interactions remain incompletely understood. In this study, we identified a tomato mutant exhibiting significantly reduced plant height. Through gene cloning and bulked segregant analysis (BSA) sequencing, we found that the mutant gene corresponds to the tomato auxin response factor gene SlARF5/MP. Here, we show that overexpression of SlARF5/MP significantly enhances plant height. Additionally, treatment with GA3 restored the plant height of the mutant to wild-type (WT) levels, indicating that GA content is a key factor influencing plant height. We also observed significant upregulation of GA-biosynthesis genes, including GA2-oxidases GA20ox3 and GA20ox4, as well as the GA3 biosynthesis gene GA3ox1, in SlARF5-overexpressing plants. Furthermore, we demonstrated that SlARF5 directly binds to SlGA2ox3, which mediates the conversion of GA3 to inactive GA, therebyregulating its expression. Our findings suggest that SlARF5 modulates GA3 metabolism by regulating GA synthesis genes, ultimately leading to alterations in plant height.

Verification of the Fusarium‐Increasing Properties of the Dominant Dwarfing Gene Ddw1 in triticale (×Triticosecale)

ABSTRACTDwarfing genes that are considerably reducing plant height are used in many cereals. In triticale, the rye‐derived dominant dwarfing gene Ddw1 was introgressed in commercial varieties. It has already been shown that this gene increases Fusarium head blight (FHB) susceptibility in one segregating population. We aimed for verifying this effect in the genetically unrelated doubled haploid (DH) population Cando (Ddw1) × Tritikon (ddw1), with 182 progenies in an experiment with artificial inoculation across six location–year combinations (environments). Linkage mapping was performed with DArTseq markers. The progenies significantly (p < 0.001) varied for FHB severity, plant height and heading stage with high entry‐mean heritabilities (0.85–0.98). The population showed a bimodal distribution for plant height. A significant QTL on chromosome 5RL was found for all three traits explaining 38%, 62% and 43% of the genotypic variation for FHB severity, plant height and heading stage, respectively, and most likely representing Ddw1. This gene increased FHB severity by 5.6 percentage points, delayed heading by 2.7 EC stages and reduced plant height by 29.6 cm on average. To use this gene in practical triticale breeding, the genetic background must be enriched with FHB resistance QTL to counterbalance the negative effect of Ddw1 either by introgression of major FHB QTL from exotic sources or by genomic selection within the adapted gene pool.

Effects of nickel, lead, and copper stress on the growth and biochemical responses of Aegilops tauschii seedlings

Heavy metal pollution causes severe abiotic stress in cereal crops around the world. This study investigated the effects of different concentrations (0, 100, 200, and 300 mg·kg–1) of nickel, lead, and copper stress on the growth and biochemical responses of Aegilops tauschii seedlings, to provide a reference for research on the mechanism of invasion and screening potential sources of wheat tolerance genes. The results showed that nickel, lead, and copper stress caused a significant decrease in the contents of chlorophyll a, chlorophyll b, and chlorophyll (a + b) in A. tauschii, thereby inhibiting photosynthesis to different degrees and hindering seedling growth, which was reflected in significant reductions in plant height and root length, with the most notable effect observed under stress by 300 mg·kg–1 lead. As the concentration of heavy metals increased, the activities of antioxidant enzymes (SOD, POD, and APX), non-enzymatic antioxidants (GSH and AsA), and the contents of osmotic regulatory substances (proline and soluble proteins) in A. tauschii significantly increased. Additionally, heavy metal stress increased H2O2 and TBARS levels. However, when the nickel, lead, and copper concentrations reached 300 mg·kg–1, no significant differences were found in H2O2 or TBARS levels compared to those in the CK group. To summarize, A. tauschii can mitigate the accumulation of ROS and membrane lipid peroxidation caused by heavy metal stress through self-regulation, thus exhibiting a certain degree of tolerance to stress caused by different concentrations of nickel, lead, and copper. Finally, the evaluation using the membership function method revealed that among the three heavy metals, A. tauschii exhibited the strongest adaptation to Cu, followed by Ni and Pb.

Impact of Salinity Stress on Soybean Growth and Yield under Saturated Soil Culture in Tidal Lands: A Comparative Study of Tolerant Varieties

Salinity stress, intensified by climate change events such as El Niño and drought, presents a significant challenge to soybean production in tidal lands. This study evaluated soybean varieties’ growth, tolerance, and yield under varying salinity conditions within a saturated water cultivation system. The experiment was conducted from February to May 2024 at the IPB Experimental Station in Leuwikopo, Bogor, Indonesia, using soil samples collected from type B tidal lands in Mulyasari Village, Banyuasin, South Sumatra. A completely randomized design (CRD) was employed with three factors and three replications each. The first factor was soybean variety (“Demas-1” and “Detap-1”), the second was soil salinity (0 and 2000 ppm NaCl), and the third was irrigation salinity at different growth stages (control, 2000 ppm NaCl before/during flowering, and 2000 ppm NaCl after flowering). The results demonstrated that the “Demas-1” variety exhibited superior growth characteristics, including higher leaf greenness, dry weight of root nodules, and number of filled pods per plant. Exposure to soil salinity of 2000 ppm NaCl led to a significant reduction in plant height (29.38%), leaf number (38.01%), leaf greenness (28.67%), dry weight (49.90%-60.80%), and filled pods per plant (55.51%), while increasing plant toxicity (108%). Irrigation with 2000 ppm NaCl further exacerbated these negative impacts, resulting in decreased leaf greenness (15.42%-18.06%) and filled pods per plant (17.84%-23.94%). The interaction between soybean variety, soil salinity, and irrigation salinity significantly influenced the number of filled pods per plant. The combination of any soybean variety with 2000 ppm NaCl resulted in a reduction of filled pods per plant. Moreover, applying saline irrigation after flowering to saline soil decreased the number of filled pods per plant by 64.68%. These findings highlight the critical importance of selecting tolerant soybean varieties and implementing effective irrigation management strategies to mitigate the adverse effects of salinity on soybean production in tidal lands.

Wheat genetic progress in biomass allocation and yield components: A global perspective

BackgroundWheat is an essential food source and is subjected to intense breeding efforts for increased grain yield, but stagnation in grain yield improvements has been reported in many regions. The identification of genetically linked factors impeding further progress in wheat grain yield improvement is therefore urgently required. MethodA comparative meta-analysis of data from 66 publicly available field experiments involving multiple wheat genotypes was performed to identify traits altered in breeding programs, their relationship with grain yield, and their past and current impact on grain yield increases. ResultsWheat grain yield can be increased by increasing either the aboveground biomass (ABM) or the harvest index (HI). However, there was no correlation between these traits since a reduction in plant height can occur with increases in the HI and overall grain yield, but with no reduction in the ABM. The combined data from 32 global datasets revealed a substantial increase in wheat grain yield from 1860 to 2017, accompanied by improvement in HI and yield components. When considering only the genotypes introduced from the 1960s to 2017, there was a linear increase observed in both grain yield and HI until the mid-1980s. However, genetic progress in HI and GY has slowed down since then. Before the mid-1980s, there was a decreasing trend observed in plant height which remained relatively static thereafter. While ABM did not exhibit significant increases during this period. After the mid-1980s, significant improvements have been observed in ABM; however, no obvious increase were observed in other yield components. ConclusionsSince the 1980s, there has been an increase in the aboveground biomass of wheat, while grain weigth and grains per m2 increases trending slowly, and both harvest index and grain yield have almost stagnated. Therefore, increasing grains per m2 and/or grain weight should be the major research direction to further improve the wheat harvest index and grain yield in the future. ImplicationsThe systematic study of changes in wheat traits in past breeding efforts for improved grain yields has provided useful indicators for the direction of wheat breeding in the future.

Phenotypic characterization and genetic mapping of the semi-dwarf mutant sdw9 in maize.

In summary, we characterized a maize semi-dwarf mutant, sdw9, and successfully isolated the responsible gene, which encodes a GRAS protein, through a combination of map-based cloning and Re-sequencing (Re-seq). Our findings demonstrate that the candidate gene ZmGRAS42 regulates BR signaling genes, thereby influencing internode development. This regulatory function likely involves processes such as cell division, cell cycle regulation and cell wall synthesis. Favorable variations of ZmGRAS42 identified in this study may hold promise for the development of lodging-resistant maize cultivars suitable for high-density planting, contributing to the improvement of maize breeding programs. Plant height and lateral root angle are crucial determinants of plant architecture in maize (Zea mays) which are closely related to lodging resistance at high planting density. These traits are intricately regulated by various phytohormones. Mutations affecting hormone biosynthesis and signaling often lead to reduced yield alongside diminished plant height, posing challenges in breeding dwarf maize varieties. In this study, the maize mutant sdw9 was characterized, which displays shorter stature and altered lateral root angle compared to WT, while showing potential to increase planting density and improve overall yield despite a slight reduction in single-ear yield. Employing positional cloning coupled with Re-seq techniques, we pinpointed a transposon insertion in the candidate gene ZmGRAS42, which encodes a GRAS transcription factor involved in BR signaling in maize. Transcriptome analysis revealed that ZmGRAS42 orchestrates the expression of several known dwarfing genes such as D8, Br2, and Na2, along with genes associated with cell wall organization, cell division, and cell cycle regulation, notably Cesa4, Cesa7, and Cyc11. Furthermore, identification of favorable ZmGRAS42 haplotypes linked to reduced plant height offers novel avenues for maize breeding strategies. These findings not only hold the potential for enhancing maize lodging resistance but also for optimizing land utilization through high-density planting practices.

Enhancing Agro Morphological Traits of three Unique Traditional Rice Landraces of Chhattisgarh through Gamma Ray-Irradiation

Mutation breeding is a simple and effective technique for generating genetic variation within crops. Mutagens such as Gamma radiation induce changes in their DNA that could lead to the development of new traits, such as improved yield or disease resistance. In the present study, Gamma ray mutagenesis was performed on three traditional rice varieties (Gudma dhan, Dawar dhan, and Lohandi dhan) to identify potentially beneficial mutants with desirable agro-morphological agricultural characteristics. The major constraints to address were their tall statures and weak culms, fewer panicles and tillers, and late maturity. Using a fixed dose of 300 Gy, 35 mutants were identified in Dawar dhan, 33 in Gudma dhan, and 21 in Lohandi dhan. The selected mutants showed an average reduction in plant height that ranged from 42.69% to 33.11%, as compared to their respective landraces. Also, a substantial reduction (ranging from 3.08%-10.55%) in days to 50% flowering was observed. Importantly, these mutants showed an increase in yield of 38.11% (Dawar dhan), 32.63% (Gudma dhan), and 7.0% (Lohandi dhan). These findings demonstrate the utility of mutation breeding through Gamma radiation in alleviating the key constraints inherent to traditional rice landraces.

The Effects of Different Grazing Periods on the Functional Traits of Leymus chinensis (Trin.) Tzvelev in a Typical Inner Mongolia Steppe

Plant functional traits are effective indicators and predictors of environmental change, revealing plants’ ecological countermeasures and adaptability through phenotypic plasticity. We conducted a 6-year grazing experiment on typical temperate grassland to assess the impact of different grazing periods on the plasticity and variability of the functional traits of Leymus chinensis and the relationship between traits and individual plant biomass. Our study included four treatments: CK (enclosure), T1 (grazing in May and July), T2 (grazing in June and August), and T3 (grazing in July and September). The results for 13 functional traits indicated that the T3 treatment showed the smallest reduction in individual plant biomass, plant height, leaf area, stem length, and leaf length, making it the most effective type of grassland management and optimal for the maintenance and restoration of L. chinensis traits. Under T1, T2, and T3, the plasticity of stem weight, total leaf weight, total leaf area, and stem length was higher and crucial for regulating individual plant biomass. The results underscore that the changes and plasticity of dominant species under grazing treatments are key to understanding the relationship between ecosystem function and grassland management. This study provides a theoretical basis and data support for the adaptive utilization and restoration management of typical grassland resources.

Plant growth regulator effects on red fescue seed crops in diverse production environments

AbstractStrong creeping red fescue (Festuca rubra L. spp. rubra Gaudin) is a cool‐season perennial turfgrass widely used in temperate and subalpine regions around the globe. Although creeping red fescue turf is tolerant of shade, low fertility acidic soils, and drought conditions, creeping red fescue seed crops grown in optimal growing environments can lodge, ultimately reducing yield in regions where this important turfgrass is grown for seed. To address this issue, we investigated the effects of two plant growth regulators (PGRs), chlormequat chloride (CCC) and trinexapac‐ethyl (TE), on plant height, lodging, and seed yield of strong creeping red fescue over 9 site‐years in the Peace River region of western Canada. The study encompassed 6 site‐years with first‐year stands and 3 site‐years with second‐year stands. The PGRs were applied alone and in a TE + CCC mixture at the two‐node (BBCH 32–33, where BBCH is Biologische Bundesanstalt, Bundessortenamt and Chemische Industrie) and early head emergence (BBCH 51–52) growth stages in first‐ and second‐year stands, respectively. The application of TE, CCC, and their mixture resulted in a differential decrease in lodging and an increase in seed yield in first‐year stands. However, PGRs applied at BBCH 51–52 on second‐year stands had no effect on seed yield but reduced plant height and lodging. This study found a negative correlation between seed yield and lodging. Among the PGR treatments, the CCC + TE mixture was the most effective in reducing lodging and increasing seed yield of strong creeping red fescue.

Genetic Transformation of Triticum dicoccum and Triticum aestivum with Genes of Jasmonate Biosynthesis Pathway Affects Growth and Productivity Characteristics.

The transformation protocol based on the dual selection approach (fluorescent protein and herbicide resistance) has been applied here to produce transgenic plants of two cereal species, emmer wheat and bread wheat, with the goal of activating the synthesis of the stress hormone jasmonates by overexpressing ALLENE OXIDE SYNTHASE from Arabidopsis thaliana (AtAOS) and bread wheat (TaAOS) and OXOPHYTODIENOATE REDUCTASE 3 from A. thaliana (AtOPR3) under the strong constitutive promoter (ZmUbi1), either individually or both genes simultaneously. The delivery of the expression cassette encoding AOS was found to affect morphogenesis in both wheat species negatively. The effect of transgene expression on the accumulation of individual jasmonates in hexaploid and tetraploid wheat was observed. Among the introduced genes, overexpression of TaAOS was the most successful in increasing stress-inducible phytohormone levels in transgenic plants, resulting in higher accumulations of JA and JA-Ile in emmer wheat and 12-OPDA in bread wheat. In general, overexpression of AOS, alone or together with AtOPR3, negatively affected leaf lamina length and grain numbers per spike in both wheat species. Double (AtAOS + AtOPR3) transgenic wheat plants were characterized by significantly reduced plant height and seed numbers, especially in emmer wheat, where several primary plants failed to produce seeds.

Maize-Tripsacum-Teosinte allopolyploid (MTP), a novel dwarf mutant inducer tool in maize.

Dwarf plant architecture facilitates dense planting, and increased planting densities boost the maize yield. However, breeding applications of dwarfing materials for maize are currently limited. There is an urgent need remove the obstacles to applying dwarf resources. Here, we innovated a new method to add a novel maize dwarf germplasm through the distant hybridization of Maize-Tripsacum-Teosinte allopolyploid (MTP) with maize. We identified ten independent dwarf families with unique characteristics. Five germplasms in our library were controlled by their respective dwarf genes. However, no allele was controlled by Br2. Subsequently, d024 in the library was successfully fine mapped, revealing its linkage to indel-4 in ZmCYP90D1. The indel-4 polymorphism regulates the expression of ZmCYP90D1 and is controlled by an upstream transcription factor (ZmBES1/BZR1-5). The indel-4 of ZmCYP90D1 allele, which reduces plant height, originated from Tripsacum, a wild variety of maize. However, d024 exhibits sensitivity to brassinosteroids (BRs), with lower castasterone levels in the internodes than that in the wild type. Furthermore, ZmCYP90D1 interacted with ZmFDXs and ZmNAD(P)H to positively regulate the downstream BR synthesis pathway. Additionally, we showed that introgressing the indel-4 of the Tripsacum allele into modern hybrids ensures yield potential and improves the harvest index under high-density conditions. Overall, as we begin to manufacture highly engineered dwarf materials using the MTP, this approach will solve the problems faced by corn dwarfs.

CNGC20 plays dual roles in regulating plant growth and immunity in Brassica napus

Inflorescence architecture is determined by inflorescence length, branch angles and the density of siliques, which affects planting density, lodging resistance and mechanical operation in rapeseed. However, the molecular mechanisms controlling inflorescence architecture are poorly understood, restricting the progress of breeding varieties with ideal plant architecture in oilseed rape. In this study, we have identified and characterized a rapeseed inflorescence development mutant, reduced inflorescence length (ril), which exhibits determinate and shortened inflorescences, reduced plant height, compact branches, and increased silique density. Through BSA-seq and map-based cloning, we find that RIL encodes a cyclic nucleotide-gated channel 20 (BnaA01.CNGC20). A substitution of proline at the 304th position to leucine (P304L) was identified in the conserved transmembrane domain of BnaA01.CNGC20. This P304L substitution neither affects the subcellular localization and self-assembly of BnaA01.CNGC20, nor disrupts the interactions with BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1), which interacts with CNGC20 and phosphorylates it to regulate Ca2+ channel stability. However, the P304L substitution increases channel activity and Ca2+ influx, which in turn induces immune responses such as cell death, H2O2 accumulation, upregulation of pathogenesis-related genes, and pattern-triggered immunity. The enhanced immunity improves the resistance to Leptosphaeria biglobosa and Sclerotinia sclerotiorum. Transcriptome analysis further revealed that CNGC20 plays dual roles in regulating plant growth and immunity via the brassinosteroid and auxin signaling pathways. The findings in this study provide deeper insights into the intricate relationship between cytosolic Ca2+ level and plant development and immunity, as well as the trade-off between immunity and the performance of yield-related traits in the heterozygous plants (+/ril), which may serve as a guide for balancing yield and disease resistance in oilseed rape breeding.

Evaluation of the growth, enzymatic activity, electrolyte leakage, and phytoremediation efficiency of Conocarpus erectus under cadmium and lead stress.

Contamination of agricultural soil by heavy metals poses a significant threat to soil quality and crop yields. Using plants as a natural remediation approach attracts researchers' attention around the world. A 16-month pot experiment was conducted using Conocarpus erectus in a randomized complete block design. The growth, enzymatic activity, electrolyte leakage, and remediation potential were estimated under Cd nitrate]40 low (L), 60 medium (M), 80 high (H) mg/kg soil [and Pb nitrate]400 (L), 700 (M), 1,000 (H) mg/kg soil [applied individually and in combination. Conocarpus erectus demonstrated a good tolerance (over 70%) against lower and medium cadmium (Cd) and lead (Pb) levels and a medium resistance against high Cd and Pb levels, with a survival rate of 100% under all the treatments used. The most negative treatment on the growth traits and tolerance of C. erectus was (H) Cd and (H) Pb, which reduced plant height; chlorophyll index; dry weights of the leaves, stems, and roots; root length; and tolerance index of biomass and roots by 25.87%, 48.97%, 50.56%, 47.25%, 58.67%, 50.18%, 51.00%, and 50% in comparison to the respective control, consecutively. Relative to the control, all Cd and Pb applications increased polyphenol oxidase (PPO), peroxidase (POD), and catalase (CAT) activities, and the increment was parallel up to medium Cd and Pb levels and then decreased with their high levels but still higher than the control. Electrolyte leakage (EL) was upheaved by raising the levels of Cd and Pb, and it reached the maximum (52.79%) at the (H) Cd (H) Pb treatment. Cd and Pb in the leaves, stems, and roots were boosted by raising their levels in the treatments. Conocarpus erectus is considered a phytoextractor for the Cd levels used because the bioconcentration factor of the stem (BCFs) and the translocation factor (TF) of Cd were >1, and it is a suitable plant for Pb phytoextraction at (L) Pb, (M) Pb, and (M) Cd (M) Pb levels because its Pb BCFs and bioconcentration factor of the root (BCFr) were <1 and its Pb TF was >1. On the other hand, C. erectus is considered a phytostabilizator for Pb at (H) Pb, (L) Cd, (L) Pb, and (H) Cd (H) Pb levels because its Pb BCFs, BCFr, and TF were <1.

Responses of Khao Dawk Mali 105 and Pathum Thani 1 Rice to Different Soil Moisture Regimes on Physiological Traits and Productivity

Khao Da wk Mali 105 (KDML105) and Pathum Thani 1 (PTT1) are two popular rice cultivars in Thailand; KDML105 is known for its unique texture and fragrance and PTT1 for its high yield and ability to be grown year-round in various conditions. This research aimed to (1) study the morphological and physiological processes of two rice cultivars KDML105 and PTT1 under six levels of soil moisture including 20, 30, 40, 50, 60, and 70% available water holding capacity (AWHC) in clay soil and sandy clay loam soil (SCL); (2) identify the critical soil moisture content (CMC) using the physiological response to drought. All physiological traits decreased with reduced soil moisture levels across all growth stages and soil types. The 20% AWHC maximum reduced plant height (1.61-folds), predawn leaf water potential (LWPpd, 3.07-folds), net photosynthesis rate (3.26-folds), stomatal conductance (17.00-folds), chlorophyll fluorescence (1.28-folds), dry matter (2.70-folds), grain yield (3.91-folds) in flowering stage. All physiological traits positively correlated with dry matter and grain yield in both cultivars and both soils, but the highest correlation was found between LWPpd with dry matter (0.884–0.961**) and grain yield (0.790–0.936**) in PTT1, or dry matter (0.883-0.973**) and grain yield (0.818–0.945**) in KDML105. Therefore, LWPpd was used to evaluate the CMC from the linear regression between LWPpd and soil moisture contents. At the seedling stage, the CMCs of PTT1 were at 60% AWHC in both soils, while KDML105 was at 60 and 70% AWHC in clay and SCL soils, respectively. At the tillering and flowering stages, the CMCs of both cultivars were at 70% AWHC in both soils. The results indicate that CMC values vary with soil texture, rice cultivar, and growth stage. This information is crucial for optimizing irrigation practices, such as implementing alternate wetting and drying systems tailored to specific soil textures and rice cultivars.

GhCASPL1 regulates secondary cell wall thickening in cotton fibers by stabilizing the cellulose synthase complex on the plasma membrane.

Cotton (Gossypium hirsutum) fibers are elongated single cells that rapidly accumulate cellulose during secondary cell wall (SCW) thickening, which requires cellulose synthase complex (CSC) activity. Here, we describe the CSC-interacting factor CASPARIAN STRIP MEMBRANE DOMAIN-LIKE1 (GhCASPL1), which contributes to SCW thickening by influencing CSC stability on the plasma membrane. GhCASPL1 is preferentially expressed in fiber cells during SCW biosynthesis and encodes a MARVEL domain protein. The ghcaspl1 ghcaspl2 mutant exhibited reduced plant height and produced mature fibers with fewer natural twists, lower tensile strength, and a thinner SCW compared to the wild type. Similarly, the Arabidopsis (Arabidopsis thaliana) caspl1 caspl2 double mutant showed a lower cellulose content and thinner cell walls in the stem vasculature than the wild type but normal plant morphology. Introducing the cotton gene GhCASPL1 successfully restored the reduced cellulose content of the Arabidopsis caspl1 caspl2 mutant. Detergent treatments, ultracentrifugation assays, and enzymatic assays showed that the CSC in the ghcaspl1 ghcaspl2 double mutant showed reduced membrane binding and decreased enzyme activity compared to the wild type. GhCASPL1 binds strongly to phosphatidic acid (PA), which is present in much higher amounts in thickening fiber cells compared to ovules and leaves. Mutating the PA-binding site in GhCASPL1 resulted in the loss of its colocalization with GhCesA8, and it failed to localize to the plasma membrane. PA may alter membrane structure to facilitate protein-protein interactions, suggesting that GhCASPL1 and PA collaboratively stabilize the CSC. Our findings shed light on CASPL functions and the molecular machinery behind SCW biosynthesis in cotton fibers.

Biogas slurry: A potential substance that synergistically enhances rapeseed yield and lodging resistance

Biogas slurry (BS) plays a vital role in improving the efficiency of crop production. On the flip side, the impact of BS on plant lodging factors and yield related traits is still obscure. Hence, we aimed to study the effects of pig and cow BS applications on yield formation, morpho-anatomical, mechanical, physiological properties and transcript expression patterns. The results showed that the yield and lodging resistance of rapeseed were synergistically improved via applying full BS dosage versus nitrogen fertilizer (CK). In addition, the seed yield was significantly increased by 23.9 % by promoting the dry matter accumulation and transport-ability, increasing number of pods by 8.4 % and 1000-seed weight by 5.1 %, respectively. Moreover, BS developed the stem mechanical strength by decreasing lodging index by 34.2 %, which was manifested by an increase in stem thickness and stiffness and a reduction in plant height. Besides, it enhanced the photosynthesis through promoting chlorophyll synthesis, delaying plant senescence, and accumulating N and K concentration. Anatomical observations revealed that BS increased greater number and area of stem vascular bundles, vessels, and maintained a dense microstructure than CK. Also, it boosted pectin, Ca2+ and K+ contents, which were significantly positively correlated with stem mechanical strength and reduced cellulose, lignin and hemicellulose contents. Meanwhile, correlation and structural equation modeling analysis validated the above results. Additionally, the differentially expressed genes were enriched in cell wall formation pathway, especially about the biosynthesis of pectin (PME, PG and PL), cellulose (CesA and CSL), lignin (PAL, POD, CCR, LAC and COMT) and hemicellulose (XTH and Xyl) were identified under BS. The above-mentioned results indicated that BS simultaneously affected lodging behavior by altering structural carbohydrates and modified yield composition by regulating dry-matter accumulation and allocation. This is the first comprehensive strategy on synchronizing rapeseed yield increase and lodging resistance under optimized BS management.

Combined toxicity of multiwall carbon nanotubes and cadmium on rice (Oryza sativa L.) growth in soil

The comprehensive effects of nanoparticles and coexisting heavy metals on plant growth are still unclear, especially in soil medium. The single and combined effects of multiwall carbon nanotubes (MWCNTs) and cadmium (Cd) on rice (Oryza sativa L.) growth were examined in this study through a 4 months pot experiment in 2022. Rice plants were exposed to different concentrations of MWCNTs (100 and 500 mg kg−1) in the presence of 5.0 mg kg−1 Cd stress. At the tillering stage, the 500 mg kg−1 MWCNTs addition reduced plant height by 8.0% and increased soluble protein content in the leaves by 13.7%, demonstrating that a single MWCNTs had a slight negative impact on rice growth. When exposed to Cd stress, the inclusion of 500 mg kg−1 MWCNTs led to a 6.7%–9.0% decrease in bioavailable Cd level in soil, resulting in considerable reductions in Cd content in roots (23.4%–29.9%), shoots (24.5%–28.3%) and grains (28.3%–66.2%). Compared to the single Cd treatment, the O. sativa L. leaves treated with Cd and MWCNTs (500 mg kg−1) had considerably reduced levels of malondialdehyde (MDA), soluble protein, and activities of antioxidant enzymes (POD, CAT, and SOD). The findings of this study indicated that appropriate concentrations of MWCNTs application in soil could alleviate Cd-induced toxicity on rice growth.

The MdIAA29-MdARF4 complex plays an important role in balancing plant height with salt and drought stress responses.

Breeding dwarf apple (Malus domestica) varieties is a recent trend in agriculture because such varieties are easy to maintain and have high yields; however, dwarf apple trees generally have poor stress tolerance. Balancing apple plant height and stress response has been an important breeding goal. In this study, aux/indole-3-acetic acid 29 gene in apple (MdIAA29) overexpression lines (#1, #2, #3) had reduced plant height by 39%, 31%, and 35%, respectively, suitable for close planting applications. Surprisingly, the dwarf MdIAA29-overexpression lines also showed increased plant tolerance to salt and drought stresses. Further analysis showed that MdIAA29 inhibited the regulation of auxin response factor 4 (ARF4) on Gretchen Hagen 3.9 (GH3.9) gene and 9-cis-epoxycarotenoid dioxygenase 3 (NCED3) gene in apple and changed the contents of auxin and abscisic acid in different tissues, thus achieving a balance between plant height and stress tolerance. In addition, we also found that MdIAA7 enhanced the inhibitory effect of MdIAA29 on MdARF4. In brief, the MdIAA29-MdARF4 complex significantly impacts the height of apple plants and their ability to respond to salt and drought stress.