Melon Roots Research Articles

Effect of soil temperature on disease development in melon plants infected by Monosporascus cannonballus

The effect of soil temperature on melon collapse induced by Monosporascus cannonballus was studied in the laboratory and in the field. In the laboratory, ascospore germination and hyphal penetration into melon roots were enhanced by increasing the temperature from 20 to 32°C. The optimum temperature for mycelial growth of five isolates of M. cannonballus was 30°C. In the field, the effect of temperature was studied in experiments conducted during the winter and autumn cropping seasons from 1995 to 1998. Disease progress was much faster in the autumn than in the winter crop seasons. Disease incidence reached 100% in the three consecutive autumn seasons studied. In the winter seasons, however, planting date influenced disease incidence. Early planting, at the beginning of January, resulted in a low disease incidence (6–26%, 125 days after planting), whereas planting at the end of January resulted in higher disease incidence (72–88%, 95–119 days after planting). In plots in which the soil was artificially heated to 35°C during the winter season, disease incidence reached 85%, as in the autumn season. Plants grown during the winter in unheated soil, or in artificially heated soil disinfected with methyl bromide, did not collapse. Root colonization by the pathogen was higher in the autumn and in heated soil than in the winter season in nonheated soil. Fifty per cent of root segments were colonized 35, 42 and 67 days after planting in the winter‐heated, autumn and winter‐unheated plots, respectively. A high correlation was found between soil temperatures above 20°C during the first 30 days after planting and disease severity. It is suggested that soil temperature during the early stages of plant development is an important factor in disease development and the expression of melon collapse caused by M. cannonballus.

Isolation and identification of a phosphate deficiency-induced C-glycosylflavonoid that stimulates arbuscular mycorrhiza formation in melon roots.

Melon (Cucumis melo) roots were inoculated with or without the arbuscular mycorrhizal (AM) fungus Glomus caledonium under low phosphate conditions. High-performance liquid chromatography analysis of the secondary metabolites in butanol extracts from roots revealed that the level of one compound in noninoculated roots showed a significant increase from 30 days postinoculation. No accumulation was observed in mycorrhizal roots and high-phosphate-supplemented roots, indicating that the accumulation of the compound was caused by a phosphate deficiency. The compound was isolated by column chromatography and identified by spectroscopic methods to be a C-glycosylflavone, isovitexin 2''-O-beta-glucoside. The effect of the compound on mycorrhizal colonization in melon roots was examined under low (0.05 mM) and high (2 mM) phosphate conditions. The degree of mycorrhizal colonization in control roots grown under high phosphate conditions (8.8%) was much lower than when grown under low phosphate conditions (22%). The treatment of roots with the compound at concentrations of 20 and 50 microM increased root colonization under both low and high phosphate conditions. In particular, the degrees of mycorrhizal colonization in treated roots grown under high phosphate conditions (25 and 22% at 20 and 50 microM, respectively) were comparable to that in untreated control roots grown under low phosphate conditions (22%). These findings suggest that the phosphate deficiency-induced C-glycosylflavonoid is involved in the regulation of AM fungal colonization in melon roots.

Arbuscular mycorrhizal fungus-promoted accumulation of two new triterpenoids in cucumber roots.

Cucumber (Cucumis sativus L.) roots were analyzed by HPLC and TLC for their levels of secondary metabolites upon inoculation with the arbuscular mycorrhizal fungus, Glomus caledonium. Three compounds in EtOAc extracts from the mycorrhizal roots showed significant increases six weeks after inoculation. These compounds were isolated by column chromatography and determined to be two novel triterpenes, 2beta-hydroxybryonolic acid (2beta,3beta-dihydroxy-D:C-friedoolean-8-en-29-oic acid) and 3beta-bryoferulic acid [3beta-O-trans-ferulyl-D:C-friedooleana-7,9(11)-diene-29-oic acid], and the known triterpene, bryonolic acid, by spectroscopic methods. Time-course experiments showed that the levels of the three terpenoids in cucumber roots were significantly increased by the application of a 53-microm sieving from a soil inoculum of the arbuscular mycorrhizal fungus containing soil microbes but no mycorrhizal fungi, and that mycorrhizal colonization further promoted the terpenoid accumulation. Inoculation with Glomus mosseae also enhanced the accumulation of the triterpenes, whereas no accumulation was observed by inoculating with the fungal pathogen, Fusarium oxysporum f. sp. cucumerinum. 2Beta-hydroxybryonolic acid was also isolated from the roots of melon and watermelon.

Scanning electron microscopy of germinated ascospores of Monosporascus cannonballus

Ascospore germlings of Monosporascus cannonballus attached to melon roots were examined with the scanning electron microscope. Results showed that ascospores germinated with one to three germ tubes. Sixty percent of the ascospores germinated with two germ tubes. No germ pores were observed. Instead, germ tubes emerged from a single linear fissure on each ascospore. The largest fissure measured 25 μm in length and 6 μm at its greatest width. Germ tubes of ascospore germlings were firmly anchored to melon roots. However, no structures resembling appressoria were observed. Rather, the tips of germ tubes, upon contact with the epidermis, appeared to have penetrated the epidermis directly. When the germ tube at the point of attachment was dislodged, no infection peg was present at the germ tube tip.

Possible involvement of a phosphate deficiency-induced C-glycosylflavone in the phosphate-mediated regulation of arbuscular mycorrhizal colonization in melon roots

Possible involvement of a phosphate deficiency-induced C-glycosylflavone in the phosphate-mediated regulation of arbuscular mycorrhizal colonization in melon roots

Possible involvement of a phosphate deficiency-induced C-glycosylflavone in the phosphate-mediated regulation of arbuscular mycorrhizai colonization in melon roots

Possible involvement of a phosphate deficiency-induced C-glycosylflavone in the phosphate-mediated regulation of arbuscular mycorrhizai colonization in melon roots

Glasshouse studies on the effects of time, temperature and amendment of soil with broccoli plant residues on the infestation of melon plants by Meloidogyne incognita and M. javanica

AbstractThe effects of heating, over a range of temperatures and for increasing periods of time, and of adding finely chopped broccoli leaves to soil infested by Meloidogyne incognita and M. javanica on nematode infestation of melon, were studied in glasshouse experiments. There was a significant interaction between the effects of soil temperature, the period for which this temperature was maintained and broccoli amendment. At the lowest temperature tested (20°C), adding broccoli to the soil had very little effect on nematode infestation or galling of melon. Increasing the temperature of the broccoli-amended soils to 25, 30 or 35°C dramatically reduced infestation and galling compared to that in non-amended soils. Within this range, the effect of broccoli-amendment occurred sooner at higher temperatures. Heating the soil to 40°C for 10 days generally eliminated nematode infestation and root-galling, irrespective of whether broccoli had been added. Fewer egg masses were obtained from melon roots grown in broccoli-amended soils than from those grown in non-amended soils, even when roots exhibited similar degrees of galling. The results suggest that the temperature and time treatments using soil solarisation to control M. incognita or M. javanica could be reduced in soils amended with broccoli residues.

Comparisons of Root Morphology in Susceptible and Tolerant Melon Cultivars before and after Infection by Monosporascus cannonballus

The fungus Monosporascus cannonballus Pollock and Uecker infects melon (Cucumis melo L.) roots and causes root rot/vine decline disease, which has reduced productivity of commercial muskmelon and honeydew cultivars in South Texas. To assess the impact of the fungus on several root traits, two greenhouse experiments were carried out over two seasons. A comparison of inoculated vs. control root systems was carried out with four melon cultivars representing both susceptible (`Magnum 45' and `Caravelle') and tolerant types (`Deltex' and `Doublon'). The sand medium was inoculated with 50–60 colony forming units (CFUs) per gram of the severe Monosporascus strain, TX90-25. After a 30-day growth period, the control and inoculated root systems were carefully cleaned and evaluated. Roots were scanned by a computer and the data were analyzed by the Rhizo Pro 3.8 program. The traits of interest included total root length, average root diameter, number of root tips, number of fine roots (0–0.5 mm), and number of small roots (0.5–1 mm). Significant differences existed between the two tolerant cultivars and the two susceptible ones for four of the traits. Total root length, fine and small root length, and root tip number were greater for `Deltex' than for both susceptible cultivars and greater for `Doublon' than for `Caravelle'. The results suggest that tolerance to this pathogen is closely linked to the integrity of the root structure. The potential for improving root vigor to combat root rot/vine decline merits further investigation.

470 Narrow-sense Heritability Estimates for Melon Root Traits

Improving melon root systems by traditional breeding is one component of the program to develop multiple-stress-resistant melons at the Texas Agricultural Experiment Station, Weslaco. Ten diverse melon lines representing four horticultural groups were intercrossed utilizing a Design II mating scheme. The male parents were: `PI 403994,' `Perlita,' `Doublon,' `Caravelle', and `PI 525106.' The female parents were: `Créme de Menthe,' `Magnum 45,' `BSK,' `PI 124111 × TDI', and `Deltex.' F1 progeny were grown in pasteurized sand in the greenhouse using a randomized complete-block design with four reps. After 4 weeks, root systems from all plants were carefully washed to remove the sand. Each root system was then placed onto a glass, plated, and scanned into the computer software Rhizo Pro 3.8 (Regent Instruments, Quebec). This software calculated root lengths of various diameter classes, root area, and root tip number. All data was input into Agrobase software for calculation of genetic variances based on Design II analysis. Significant differences of contributions by male parents to progeny variation were few. Only length of roots with 1.0- to 1.5-mm-diameter and vine length were significantly different. Differences in contributions by female parents to all traits except root tip number were highly significant. No significant interaction effects were observed for any trait. Narrow-sense heritability estimates were moderate to high for all traits. The range was from 0.56 for root tip number by males to 0.81 for both length of 0.5- to 1.0-mm-diameter roots and vine length for females. Estimates for total root length (0.76) and root surface area (0.77) were high. The lack of male by female interaction suggests very low dominance genetic variation and contributed to high heritability estimates, which represent predominantly additive gene action. Additive genetic variation allows more-efficient progress by selection, making the potential for root system improvement favorable.

Occurrence and Pathogenicity of Fungi Associated with Melon Root Rot and Vine Decline in California.

The occurrence of fungi associated with root rot and vine decline of melon (Cucumis melo) in commercial fields in California was surveyed over 3 years. The fungi most frequently isolated from discolored vascular tissue or root rot were Acremonium cucurbitacearum, Rhizopycnis vagum, Monosporascus cannonballus, Fusarium solani, Macrophomina phaseolina, Pythium spp., and Verticillium dahliae. The frequency of isolation of the various fungi varied with root symptomology. Pythium spp., and M. phaseolina were frequently associated with a wet, brownish root rot, while A. cucurbitacearum, R. vagum, and Rhizoctonia solani were generally associated with a dry, corky root rot. Presence of Monosporascus cannonballus was associated both with a wet, brownish rot as well as with discrete, reddish, corky lesions. The frequency of isolation of a given pathogen varied with geographic location, with M. cannonballus present only in the southern production areas, while A. cucurbitacearum and Rhizopycnis vagum were most common in the northern production areas. In pathogenicity tests in field microplots, M. cannonballus caused vine collapse and severe root rot of cantaloupe, reducing root length density by 93%. California isolates of R. vagum and A. cucurbitacearum, although only weakly pathogenic in field microplots, caused root discoloration and reduced vine growth in greenhouse tests. Reduction in dry weight of greenhouse-grown cantaloupe was 40, 23, and 39% for R. vagum, A. cucurbitacearum, and M. cannonballus, respectively.

Does calcium ameliorate the negative effect of NaCl on melon root water transport by regulating aquaporin activity?

The hydraulic conductance (L0 ) of detached, exuding root systems from melon (Cucumis melo cv. Amarillo oro) was measured. All plants received a half-strength Hoagland nutrient solution, and plants stressed either solely with NaCl (50 mM) or with NaCl (50 mM) following treatment (2 d) with CaCl2 (10 mM) were compared with controls and CaCl2 -treated (10 mM) plants. The L0 of NaCl-treated plants was markedly decreased when compared to control and CaCl2 -treated plants, but the decrease was smaller when NaCl was added to plants previously treated with CaCl2 . A similar effect was observed when the flux of Ca2+ into the xylem and the Ca2+ concentration in the plasma membrane of the root cells were determined. In control, CaCl2 - and NaCl + CaCl2 -treated plants, HgCl2 treatment (50 μM) caused a sharp decline in L0 to values similar to those of NaCl-stressed roots, but L0 was restored by treatment with 5 mM DTT. However, in NaCl roots only a slight effect of Hg2+ and DTT were observed. The effect of all treatments on L0 was similar to that on osmotic water permeability (Pf ) of individual protoplasts isolated from roots. The results suggest that NaCl decreased the passage of water through the membrane and roots by reducing the activity of Hg-sensitive water channels. The ameliorative effect of Ca2+ on NaCl stress could be related to water-channel function.

Effect of Na+ on Ca2+-Binding on the Plasma Membrane of Barley Mesophyll Cells: an Electrophoretic Study

It is well known that Ca ions play an important role in mitigating the detrimental effects of high NaCl on plant growth (LaHaye and Epstein 1969, Greenway and Munns 1980, Kent and Lauchli 1985). Several reports suggest that external Na can displace Ca from the binding sites on the outer plasma membrane (PM) surface, which may be one of the primary responses to salt stress, leading to a disruption of membrane integrity and leakage of intracellular solutes; the mitigative effects of supplemental Ca may be related to the maintenance of membrane-associated Ca (LaHaye and Epstein 1969, Cramer et al. 1985, Lynch et al. 1987, Colmer et al. 1994). Cramer et al. (1985) and Lynch et al. (1987) attempted to determine whether Na displaced Ca from the plasma membrane of root cells of salt-sensitive glycophytes but failed to get any conclusive evidence, because they used an unsuitable fluorescent probe CTC for measurement of Ca bound to the cell surface (Lynch and Lauchli 1988). Recently, Yermiyahu et al. (1994), using Ca sorption technique, reported that Na ions reduced the amount of Ca sorbed to plasma membrane vesicles of salt-sensitive melon root cells. Our electrophoretic studies showed that Na ions could specifically (and nonspecifically) cause desorption of Ca from the outer plasma membrane surface of salt-sensitive tobacco cells (Murata et al. unpublished

Root System Morphology of Pepper and Melon at Harvest Stage Grown with Drip Irrigation under Desert Conditions in Baja California, Mexico.

メキシコ合衆国バハ・カリフォルニア州のゲレロ・ネグロにおいて, 日本政府とメキシコ政府の共同事業としてメキシコ沙漠地域農業開発プロジェクト(以下, プロジェクト)が実施されている.プロジェクトの目的は, 沙漠地域において点滴灌漑を用いて野菜および果樹を栽培するための技術の開発および移転にある.この目的を十分に達成するために, プロジェクトで最も重要な作物であるトウガラシとメロンの根系の形態を, 収穫期に調査した.その結果, 露地栽培のトウガラシの場合は, 根長密度が土壌表面から深くなるにつれて緩やかに減少し, 深さ20cm以下で急激に小さくなっていたが, 条直下と条間の根長密度の差は小さかった.畝立マルチ栽培のメロンの場合は, 畝の中の根長密度がかなり大きく, 畝の外では小さかった.主根から形成された側根には, 線虫の被害と考えられる多数のコブが認められた.次に, 根系形態に及ぼす点滴灌漑の影響を検討するため, 点滴チューブが配置された側と反対側における根長密度を比較した。その結果, トウガラシでは, 条の左右のいくつかの地点で, 根長密度に統計的に有意な差が認められた.一方, メロンではどの地点についても有意な差は認められなかったが, 根長密度の分布が部分的に非対称であった.以上のような根系分布の非対称性は, 点滴チューブの有無によるものと考えられる.なお, 予備調査の結果, 根長密度が高い部分で側根の形成が発達していること, とくに側根が長いことが示唆された.

Isolation of Acremonium Species Causing Postharvest Decay of Peaches in Spain.

Two Acremonium spp., A. tubakii and A. rutilum, were isolated from rotted peaches (Prunus persica (L.) Batsch 'Miraflores') after ripening at 15 and 20°C, respectively, for 10 days. Fruit harvested in September 1994 in Mula (Murcia) at a firm-ripe stage of maturity were either nontreated or washed with water at 18°C and sorted in a packing line. Sorted fruit were treated with an aqueous dilution of iprodione (Rovral 50% WP Rhône-Poulenc Agrochimie, Paris, France) at 2 g·liter-1, pH = 7, and 18°C for 5 min. Half of the iprodione-treated fruit were forced-air pre-cooled to reach 0°C at the endosperm in about 12 h. Isolations of fungi were made from subepidermic tissue of decay margins of fruit with potato dextrose agar (PDA). Fungal species were identified after axenic cultures were grown on PDA for 10 days at 30°C. Acremonium spp. were identified based on microscopic morphology of asexual reproduction structures, using taxonomic keys. No other fungi were isolated from fruit decayed by Acremonium spp. A. tubakii decayed 1.7% of the iprodionetreated and pre-cooled fruit ripened at 15 or 20°C and the fruit treated by iprodione without pre-cooling but ripened at 20°C. These fruit were completely decomposed and oozed liquid. Colonies of this species were light colored, with nonramified, nonseptate, and hyaline conidiophores. The one-cell, ovate, and hyaline conidia of the fungus were enclosed in slimy heads. A. tubakii did not cause any brown discoloration of the PDA media. A. rutilum affected 3.2% of the iprodione-treated fruit ripened at 20°C. In contrast to A. tubakii infection, A. rutilum affected only the surface of fruit, which remained dry. Cultures of A. rutilum were white to pink and the conidia were one-celled, ovate, and hyaline, forming a head on the tip of the nonramified conidiophores. Conidia were long, nonseptate, and distinct from the somatic hyphae. Acremonium spp. probably developed on injuries caused by handling and/or treatments, because these rots did not occur on untreated fruit. Rhizopus nigricans, and to a lesser extent other fungi such as Alternaria, Cladosporium, and Penicillium spp., also commonly caused decay of sampled fruit. A. tubakii is a ubiquitous soil fungus reported from various European countries. A. rutilum isolated from diseased apples were pathogenic upon reinoculation (1). Both fungi were not found in the Spanish type culture collection of 1990. Other Acremonium spp. have been identified in melon roots in Spain (2). To the best of our knowledge, this is the first report of Acremonium spp. causing decay of peach in Spain.

Populations of Nonpathogenic Fusarium oxysporum Associated with Roots of Four Plant Species Compared to Soilborne Populations

ABSTRACT The effect of the plant on the diversity of soilborne populations of Fusarium oxysporum was assessed after successive cultures of flax, melon, tomato, and wheat in separate samples of the same soil. Forty soil-borne isolates of F. oxysporum and forty root-colonizing isolates of each plant species were sampled during the first (T0) and fourth (T1) cultures. The population structures were assessed by a genotypic method based on restriction fragment analysis of polymerase chain reaction-amplified ri-bosomal intergenic spacer (IGS) DNA. Sixteen IGS types were defined among the four hundred isolates analyzed. The distributions of soil isolates among IGS types were similar at both sampling times. The structure of F. oxysporum populations associated with the roots of flax or melon did not differ from the structure of soilborne populations. In contrast, the structure of F. oxysporum populations associated with roots of wheat or tomato differed from the structure of soilborne populations. High frequencies were found for IGS type 4 among wheat isolates at both T0 and T1 and for IGS type 11 among tomato isolates at T1. Moreover, a high level of genetic divergence was obtained between IGS types 4 and 11. Our results suggest that tomato and wheat have a selective effect on soilborne populations of F. oxysporum and that this effect seems to be plant specific.

Response of melon plants to salt: 3. Modulation of GTP-binding proteins in root membranes

Summary Antisera raised against peptide sequences homologous to the conserved region of the α subunit of hetero-trimeric GTP-binding proteins (anti-G α.common antibody) from mammals and Dictyostelium discoideum cross-reacted with proteins of microsomal and plasma membranes isolated from the roots of melon (Galia, Cucumis melo L.) seedlings. In microsomal membranes the immunolabeled sets of proteins were of approximately 66, 47, 37, 30 and 22 kD. The 22 kD protein band was absent in the purified plasmalemma. Immuno-decoration of all protein bands was greatly reduced when excess purified transducin was included. The isolated microsomal membranes bound GTPγS with high affinity and specificity. The K d and the concentration of high affinity binding sites were ∼10 nmol/L and ∼5 pmol/mg total membrane protein, respectively. The nucleotide order of potency was GTPγS∼GTP>GDP≫ATP. Purified plasmalemma was relatively rich in high affinity GTPγS binding sites. Root membranes isolated from melon seedlings grown in excess NaCl exhibited a marked increase in both the concentration of GTP-binding sites and the amount of bound anti-G α-common antibody. The number of binding sites per mg protein increased as a function of the salt concentration during growth. Moreover, with a salt sensitive cultivar of melon (Eshkolit Ha’Amaqim) the response was apparent already at lower salinities. The findings identify GTP-binding proteins, presumably G proteins, in melon root membranes that carry homologous sequence as well as comparable nucleotide specificity and affinity to those of mammalian and simple eucaryotic heterotrimeric G proteins. The modulation of these proteins by prolonged salinity suggests a role for G proteins in the physiological response of plants to salination.

Outbreak of Melon Root Rot Caused by Monosporascus cannonballus in Miyagi Prefecture

Outbreak of Melon Root Rot Caused by <I>Monosporascus cannonballus</I> in Miyagi Prefecture

A model for cation adsorption to clays and membranes

A cation adsorption model is presented and its recent applications are discussed. The model combines electrostatic equations with specific binding, and considers neutral and positively charged complexes between the negative surface sites and organic cations in a closed system. Extensions in the model account for dye aggregation in solution, and for the formation of solution complexes of inorganic cations, such as [M++ Cl−]+. The amounts of 45Ca2+ adsorbed to vesicles extracted from the plasma membranes of melon root cells could be adequately simulated and predicted. The binding coefficients determined for Ca2+, Na+, and Mg2+ are in the range of values previously deduced for binding to phospholipid components. Model calculations were applied to the test of hypotheses on the effect of salt stress on the growth of roots. The adsorption of monovalent organic cations to montmorillonite is characterized by binding coefficients that are at least six orders of magnitude larger than those of Na+, Mg2+, Ca2+, and Cd2+, or those of CdCl+ or CaCl+. Monovalent organic cations were found to adsorb 140–200% of the cation exchange capacity of the clay and to cause charge reversal. Deductions from adsorption results of acriflavin are consistent with those drawn from the application of other experimental methods. Preliminary results on the adsorption of divalent organic cations are presented. Agro-environmental applications of organo-clays are discussed.

Quantitative competition of calcium with sodium or magnesium for sorption sites on plasma membrane vesicles of melon (Cucumis melo L.) root cells

The presence of Ca2+ ions in solution is vital for root growth. The plasma membrane is one of the first sites where competition between Ca2+ and other ions occurs. We studied the competition between Ca2+ and Na+ or Mg2+ for sorption sites on the plasma membrane of melon root cells. Sorption of 45Ca2+ to right-side-out PM vesicles of melon (Cucumis melo L.) roots (prepared by aqueous two-phase partitioning) was studied at various Ca2+ concentrations, in the presence of increasing concentrations of Na+ or Mg2+ chlorides. Experimentally determined amounts of Ca2+ sorbed to the plasma membrane vesicles agreed fairly well with those calculated from a competitive sorption model. The best fit of the model to the experimental data was obtained for an average surface area of 370 A2 per charge, and binding coefficients for Na+, Mg2+ and Ca2+ of 0.8, 9 and 50 M-1, respectively. Our results suggest that nonphospholipid components in the plasma membrane contribute significantly to Ca2+ binding. The high affinity of Ca2+ binding to the plasma membrane found in this study might explain the specific role of Ca2+ in relieving salt stress in plant roots.

Reduction of nitrate (13NO3) influx and nitrogen (13N) translocation by tomato and melon varieties after short exposure to calcium and potassium chloride salts

Abstract The effect of KC1 or CaCl2 pretreatments on 13NO3 influx into melon or tomato roots was investigated. Plants, previously grown in 1/10 strength Johnson's solution, were exposed for 10 min to 1/10 strength Johnson's solution supplemented with various concentrations of KCl or CaCl2. These solutions were than replaced by identical solutions labeled with 13NO3. After 10 minutes, plants were washed, roots were separated from the tops, introduced into counting vials and radioactivities counted for 30 seconds and corrected for decay. The influx of 13NO3 to the roots of melon (Cucurbita pepo L.), cultivars Rochet and Eshcolit Amakim, and tomato (Lycopersicon esculentum L.), cultivars M‐82 and VF‐785 was depressed at moderate concentrations (10–60 mol/m3) of CaCl2. By contrast, KC1 did not inhibit 13NO3 influx. Tomato plants translocated about 30% of their total 13N label to the shoot at low salt concentration. This proportion was significantly reduced by increased concentrations of KCl or CaCl2 in the ex...