A novel mineral composition increases soybean crop yield by mitigating stress induced by ultraviolet-A and -B radiation

: Ultraviolet radiation (UVR) is an important environmental abiotic stress that constantly affects the yield 12 potential of agricultural crops causing hidden yield losses and few practical solutions are available for protecting 13 large-scale field cultivation. The present study assessed the protective effect of a novel mineral composition 14 principally based upon a concentrated suspension of microparticles of crystalline and insoluble quartz sand applied 15 as foliar spray over the top of plants to mitigate the stress effects of UV-A or UV-B radiation. Soybean ( Glycine 16 max (L.) Merrill) plants were cultivated under three alternative UVR exposure scenarios (no UV, +UV-A, +UV-17 B) to compare treated and untreated plants with that composition. Measurements of malondialdehyde (MDA) and 18 proline contents demonstrated the effects of +UV-A and +UV-B on plants and the effectiveness of the foliar 19 treatment in mitigating such stress. Biometric assessment showed that root weight, foliar biomass, and number of 20 pods of untreated plants were negatively impacted by both +UV-A and +UV-B, whereas in treated plants, the 21 damages for both +UV-A and +UV-B were almost entirely mitigated. The results of this study endorse the use of 22 a promising tool for growers to achieve sustainable yield in soybeans and potentially other field crops in the face 23 of increasing challenges due to climate change.


Introduction
Ultraviolet radiation (UVR) is recognized as an important environmental abiotic stress causing negative effects on plant development and adversely impacting crop yield.Initial comprehension of morphological damage to plants caused by UVR was observed almost a century ago [6], and many authors recently and essentially concluded that UVR, particularly its UV-B component, generally causes a negative effect on plant biomass of several important crops, such as mung beans, corn, cotton, soybeans, sugarcane, rice, and wheat [13].However, few solutions exist to protect plants of any species or cultivar against UVR, leaving large-scale agricultural crops without practical management tools to address it.Solar ultraviolet radiation (UVR) reaches the planet stratosphere in three wavelength ranges: UV-A, UV-B and UV-C.As UV-C is completely absorbed by oxygen combined with the ozone layer and does not reach the Earth's surface [4,5], most prior studies have covered UV-B due to its stronger level of damage, as its photons are more able to break chemical bonds and rearrange molecular structures within plant cells [24].In contrast, there has been much less research on the effects of solar UV-A radiation, which is unaffected by stratospheric O3 depletion [27].
Agricultural crops are exposed to direct sunlight, which they need and use for photosynthesis and consequently are simultaneously receiving UV radiation, which could be a major limiting factor in the photosynthetic efficiency of crop plants [30].Failure to protect from UV-B may result in a wide range of morphological, physiological, and metabolic responses, including altered plant growth, reduced yield, damage to photosystem II (PSII), and a decrease in chlorophyll fluorescence and content [10].In a review of 129 studies on 35 crop species published since 1975, it was verified that UV-B commonly negatively impacts plant biomass and its reproductive organs [13].Even the roots of a plant, although below ground, may negatively react to the plant's leaves being exposed above ground to ambient levels of UV-B [40].As a result of UVR stress, an imbalance occurs in cellular homeostasis mainly caused by reduced photosynthesis rates and changes in plant metabolism [39] and induces ROS (reactive oxygen species), which cause lipid peroxidation and consequent damage to cell Preprint version 2 membranes [9].Under stress conditions, plants adapt through physiological and metabolic responses regulated at the transcriptional level [8,11].Ultraviolet radiation is an energetic driver of a diverse range of plant responses and may be exploitable in the context of a sustainable contribution towards the strengthening of global crop production [38].
Several major agricultural crops have been subject to assessments of UV radiation impacts [42].A study exposing corn to four UV-B doses (0, 5, 10, and 15 kJ m -2 d -1 ) demonstrated that enhanced or current ambient levels of UV-B radiation can adversely affect corn growth [25].In another study with cotton, plants were exposed to three levels of UV-B (0, 7 and 14 kJ m -2 day -1 ) in a factorial with three day/night temperatures, evidencing an interaction of UV-B and temperature that negatively impacted yield [23].A two-year study of soybeans using three cultivars with enhanced UV-B demonstrated its negative impact on yield components, with a decrease in number of pods and yield per plant by 43.7% on average [19].Another study with several soybean cultivars under the exclusion or presence of ambient UVR showed that UVR always caused a negative impact on biomass and yield over all cultivars [2].High accumulation of proline is a common physiological response in plants exposed to various abiotic stresses, including UV radiation [16].An important marker for oxidative stress in living organisms occurring in response to UV radiation is malondialdehyde (MDA) which content may rise even at minor levels of exposure to UV-A radiation [26].To address this issue, some researchers propose that breeding programs develop more adapted cultivars to UV radiation [38], particularly in response to ongoing climate change and with priority for tropical and subtropical zones.
As breeding programs require considerable lead time to deliver new high-yielding varieties, which generally takes 10 years [18], practical near-term solutions to protect large-scale field crops against excessive UV damage through exogenous treatment may be an alternative.One approach for mitigating UV stress in plants has been proposed through plant nutrition with soluble silicon (Si), as it leads to Si accumulation in the form of biogenic silica (amorphous form) under the epidermis of the leaves, which then operates as a reducer of the transmission of UVR from the external environment to the inside of the leaf [35,29].However, not all plant species or their varieties present the ability to absorb, translocate, and accumulate Si and later to form biogenic silica [34].
We hypothesized that mitigation of UV damage could be achieved by depositing a layer with fine particles of insoluble crystals of quartz silica sand on the external plant part over the leaves.Thus, we undertook a study in soybeans (Glycine max (L.) Merrill) in a greenhouse under three scenarios of UV radiation exposure (no UV, +UV-A or +UV-B) and for each situation imposing foliar sprays both with and without a suspension with a composition principally based on this mineral, followed by assessment of the plants for (1) the presence of biochemical compounds related to abiotic stress and (2) phenotype and yield parameters to determine the effects of UV-derived stress and the potential of the mineral composition in mitigating such stress.

Plant cultivation description
Seeds of soybean (Glycine max (L.) Merrill) cultivar NA5909 RG were cultivated in pots under greenhouse conditions.The pots had the capacity of 8 liters and were filled with cultivation substrate mix composed by organic material (product brand BIOMIX purchased at market and composed by crushed bark of pine / eucalyptus and powder of coconut fiber, pH 6,5, density of 300 kg.m -3 ) and sand in a proportion of 3:1 respectively.

Treatment description
The factorial design involves three UV exposure regimen (no UV, +UV-A or +UV-B) by two mitigation treatment (treated or untreated) with or without a foliar application of a composition aiming to mitigate damages by UV exposure.The composition used is as described in the Patent application WIPO/PCT WO2022/011441 (based on 45% w/v of inert, insoluble, crystal, micronized quartz sand, 12% w/v of zinc oxide and 17% w/v of manganese sulfate, presented as a concentrated suspension and purchased in the Brazilian market, branded as ACLIMAT).Four replicates were used for each treatment, being each replicate represented by one plant, thus two pots and each one having two plants were used per treatment.
For the first objective of the study (UV impact), the greenhouse was divided into three compartments (chambers) using the same anti-UV plastic film to isolate radiation from each one.The first compartment remained without UV radiation, the second was exposed to artificial UV-A radiation and the third to artificial UV-B radiation.
Irradiation for each UV type over the plants took place during 37 days from 29 DAE (days after emergence) to 66 DAE.The +UV-A chamber was irradiated with Philips TL-K 40 W/10-R lamps, always placed 60 cm above the top of the plants, emitting 1080 µW cm -2 , for 600 minutes per day (starting at 7:00 am), equivalent to 389 kJ m -2 day -1 .The +UV-B chamber was irradiated with Philips TL 40W/12 lamps, always placed 90 cm above the top of the plants, emitting 330 µW cm -2 , for 45 minutes per day (three sessions of 15 min spaced at 60 min intervals, around mid-day), equivalent to 9 kJ m -2 day -1 .The radiation intensity was measured and monitored at the top 10 cm level of the plants.The pots were rotated once a week within each chamber to ensure uniform exposure growing conditions.
For the second objective, four plants (two pots) under each of the three UV regimens were subjected (treated) to a foliar spray with 2,6 mL per plant of a water suspension of 0,5% with the composition, whereas other four plants (two pots) serving as controls were sprayed only with pure water (untreated).The first foliar spray occurred at the V3 (third vegetative node with unfolded trifoliates) crop stage and was repeated once a week for five weeks.

Biochemical analysis of plant leaves
At 84 DAE, eighteen days after radiation over plants ended, one leaflet of each trifoliate of each plant serving as replicate was extracted without the petiole, forming a bulk per plant set in layers in the same sequence of its position along the stem, then promptly measured for its fresh weight and immediately thereafter packed in aluminum ziplocked envelope and stored at -80 degrees Celsius for further analysis.For each analysis, a piece of the bulk was extracted to represent the whole plant as much as possible.

Malondialdehyde (MDA) content
Thiobarbituric acid reactive substances (TBARS) content was used to estimate lipid peroxidation.
Malondialdehyde (MDA) equivalent concentration was calculated using an extinction coefficient of 1.55 10 −5 mol −1 cm −1 , with readings between 535 and 600 nm.The results were expressed in mmoL mg −1 of fresh tissue.

Proline content
Fresh leaves were homogenized in 3% sulfosalicylic acid and filtered.The mixture filtrate was added to 1 mL each of acid ninhydrin and glacial acetic acid and was placed in boiling water for 1 h, and toluene (4 mL) was added to the mixture.Absorbance was measured spectrophotometrically at 520 nm and converted to µmol g −1 fresh weight against standard proline.The proline content was determined as described by Bates [3].

Biometric assessments of plants 2.4.1 Description of UVR impact visual assessment on leaflet
Individual plants were assessed periodically to determine the visual effect on morphological symptoms from UV stress using a scale from 1 to 5, where 1 indicated no symptoms, 2 indicated a slight reduction in leaf size, 3 indicated some crispy wrinkle aspects on leaves, 4 indicated browning and 5 indicated high symptoms of necrosis.Assessments started one week after the initiation of UV radiation and were repeated once a week, with each assessment focusing on the trifoliate recently formed and after its exposure to UVR during the preceding five to ten days, thus allowing us to obtain an average rating during plant development.

Description of UVR impact assessment on aerial biomass
Plants were harvested at 85 DAE when pods were formed and reached the R5:3 stage (grain being filled into the pod).The individual plants had their stems cut 15 cm from the soil surface, their fresh weight was measured for leaflets, and the number of pods per plant was counted.Leaflets were removed without the petiole and joined in a bulk per plant, and their fresh weight was promptly measured.

Impact on the number of pods per plant
All reproductive structures, ranging from R3 (pods just fertilized and size of 2-3 mm) to R5:3 (grain being filled into the pod), were extracted from plants and counted, with the recognition that they may not represent the final plant yield since between the stage of pod removal and plant senescence, the younger pods at the R3 or R4 stage (pod completely developed but without visible grain in it) may abort or fail to become sufficiently mature to be represented in the true final yield.The pods counted ranged from those greater than 1 cm (recent fertilized) up to pods in full grain filling, serving as an indicator of plant yield potential under stress and after mitigation.

Impact on roots
After the removal of aerial structure of the plants, the pots containing a piece of remaining stem and roots were carefully washed to remove the cultivation substrate and preserve as much root tissue as possible.To dry the cleaned roots, they were hung exposed to the sun during the entire day.The remaining debris from the cultivation substrate still attached to the roots was then removed by gently shaking it.Once clean and dry, the remaining piece of the stem and of the hypocotyl of the pivot larger than 2-3 mm was removed with scissors to assess solely the dry weight of the true root component.

Statistical analysis
Statistical analysis was performed by AgroStat software [1].Data were submitted to variance analysis by the F test, and any significant differences between treatments were compared by the Tukey test at 5% probability.

Biochemical parameters
The results of biochemical analysis of treated plant leaflets are shown in the graphs below.In the context of each UVR regimen, the same uppercase letters within treated/untreated or the same lowercase letters across UVR regimens indicate no difference by Tukey's test (P<0,05).

Malondialdehyde (MDA)
The   The use of identical uppercase letters within treated/untreated or identical lowercase letters across UVR regimens means no difference by Tukey's test (P<0,05).

Results on foliar biomass
As shown in Figure 05 (A), leaf weight is reduced in the case of either +UV-A or +UV-B exposure.Although visual symptoms of UVR damage are lighter under +UV-A exposure than under +UV-B exposure, there is a negative impact on leaf weight in both cases, with a more pronounced impact under +UV-B stress.For untreated plants, there is a reduction of 16% in leaf weight under +UV-A and of 19% under +UV-B exposure.For treated plants, the UVR effects on leaf weight are slightly reduced in both cases.

Impact on the number of pods per plant
Based on the number of pods per plant, both +UV-A and +UV-B exposure negatively impact this component of In untreated plants, exposure to +UV-A causes a 14% reduction in pod structures, whereas under +UV-B the impact is of minus 16% compared with the no UV control.In the +UV-A and +UV-B chambers, the mineral composition treatment entirely mitigates the impact of radiation, whereas no positive or negative effect is observed in the absence of UV (no UV chamber).

Discussion
Most studies concerning UVR impact in plants have focused on UV-B because of its higher energy aspect and erythemal injury, and those studies that cover UV-A effects are frequently performed in combination with UV-B, as both reach the earth surface simultaneously with sunlight.Indeed, plant responses to UV-A radiation have been less frequently studied than those to UV-B, leaving an important gap in our understanding of the perception of solar UV radiation by plants [22].
Since the UV-A wavelength (315 to 400 nm) is closer to photosynthetically active radiation (PAR, 400-700 nm), some plant species may benefit from a portion of this range of wavelengths that is closer to blue color through an increase in chlorophyll content, higher photosynthetic activities and even promotion of plant growth [33].Whereas prior studies demonstrate that UV-B causes losses in biomass and yield of most crop plants [13], many of the effects on growth and In our present study, MDA content is higher in both UV regimens in comparison with no UV and of very similar content in both +UV-A and +UV-B exposure for untreated plants, although damage observed in biomass is not necessarily of equal magnitude.Similar to what has been reported in a prior study on the responsiveness of MDA in living organisms to UV-A [26], MDA seems to be equally and highly responsive to both types of UV stress, and the data of this preset study suggest that UV-A may be as harmful as UV-B to plant physiology, indicating the accumulation of ROS in untreated plants for both UV types.The accumulation of ROS causes increased levels of peroxidation of membrane lipids, and MDA content indicates this type of cell damage [17].In our study, the MDA content from treated leaflets with the composition is significantly lower than that in A few prior studies measuring MDA and proline in connection with stress caused by UV radiation usually assayed the leaves during or immediately after exposure to UV [15,7,29].An interesting observation from this study is that leaves were collected 18 days after irradiation ended, and the variable content of these compounds was still measurable, possibly indicating that the effects of UV are long lasting in plant tissues.
In the present study, both UV-B and UV-A causes negative impacts on plant morphology, physiology, and yield potential.The assessment of visual stress on leaflets of plants shows that UV-A presents a soft visual morphological effect when compared to UV-B.However, both UV-A and UV-B causes damage to root volume, foliar biomass, and yield potential due to the amount of pods/plant.Under exposure to +UV-A and +UV-B, the impact is negative and more severe on untreated plants, in contrast to treated plants for which the mineral composition mitigates such deleterious effects.
The impact on root development caused by both wavelengths is of great importance since it will limit yield potential or cause yield variations under common field situations in the event of insufficient or irregular rain distribution.UV-B causes roots to have less dry weight or deformity due to bending induced by UV-B radiation through a flavonoid-mediated phototropic response [37], and it has been demonstrated that exposure to UV-B induces an inhibition of primary root elongation because of a decrease in cell proliferation in the meristematic zone of the primary roots [31].Here, the study assesses the effect of both frequencies of radiation (+UV-A and +UV-B) and verifies a reduction in root weight of 50% under +UV-B and 29% under +UV-A, which are very close to the observations of a prior study [12] that found a reduction of 41% under UV-B and 51% under combined UV-A/UV-B, thereby also confirming the effect of UV-A.The present study also aligns with other findings [41] that measured the root weight of soybean seedlings grown under exclusion of UV-B or at two levels of exposure (2.63 kJ m −2 .d−1 or 6.17 kJ m −2 .d−1 ) to elevated UV-B radiation and showed that both levels of exposure inhibited root growth on average by 30% dry weight compared to the control.The data presented here shows that a foliar spray with the composition (treated) attenuates the impact of both UV-A and UV-B since treated plants develops better roots, a result in conformity with root measurements in a prior study that showed higher dry root weight when soybean plants were grown under the exclusion of UVR effects by using a UV filter shield over the plot to protect the plants [12].The importance of these findings is that protecting crops through reduction of UVR exposure through common practices of foliar spray will allow improved root development, a critical feature for optimal water and nutrient extraction from the soil, contributing to higher and/or more stable yields that is impacted by exposure to ambient UV radiation, moreover in the face of climate change.
The present study shows that fresh leaf biomass of untreated plants is also impacted by both +UV-A and +UV-B in the order of -16% and -19%, respectively, and treated plants shows a slight mitigation of this negative effect, but not to the level observed in the no UV situation.The effect found remains significant and aligns with the findings of other studies [19,12].
Regarding yield, the present study confirms a previous report that UV-B causes a reduction in yield potential notably due to smaller number of pods per plant with a reduction of 25% in number of pods per plant with supplemental UV-B over ambient UV-B [15].Conversely, in a prior study applying the exclusion of UV-B on 8 soybean cultivars, an increase in number of pods per plant of up to 43% was found [2].In a 2-year study of the effects of UV-B on soybean yield, it was determined that yield reduction was mainly attributable to a change in number of pods per plant under UV-B radiation, which decreased the number of pods per plant of three soybean cultivars by 34.5% on average [19].In the present study, the yield potential represented by the number of pods per plant is impacted both by +UV-A and +UV-B, where untreated plants show minus 14% and minus 16% of pod structures under +UV-A and +UV-B, respectively, in comparison with a no UV regimen.Interestingly and as hypothesized, treated plants in the same +UV-A and +UV-B stressing environments shows stress mitigation and presents no yield loss, whereas no difference in the number of pods per plant occurs between treated or untreated plants in the absence of such UV stress.

Conclusion
Based on this study, it was possible to estimate that at least soybean may be experiencing a latent 15% yield deleterious effects of ultraviolet radiation (+UV-A and +UV-B) resulted in increased lipid peroxidation, as verified by the corresponding increase in MDA content (Figure 01).The content of MDA found in the leaves of untreated plants grown under UV is equally higher in both +UV-A and +UV-B in comparison to the control (no UV exposure), whereas for treated plants the content of MDA is increased but in a smaller slope at UV exposure situations in comparison with no UV exposure.When comparing the data from treated versus untreated plants in each UV stress situation, a reduced level of MDA is measured in treated plants under +UV-B and an even further reduced MDA content in treated plants under +UV-A, which is close to that measured in plants from the no UV chamber.In the no UV chamber the MDA content does not differ significantly between untreated and treated plants.

3. 1 . 2
Proline contentThe proline content is shown in Figure02.For untreated plants, the content of proline is higher in leaves of plants exposed to +UV-A (+27%) and much higher in those exposed to +UV-B (+66%) than in those plants under no exposure to UV.Although treated and untreated plants under +UV-B exposure show a higher proline content than those under no UV exposure, the proline content is significantly lower in treated versus untreated plants under +UV-B exposure.Treated plants show consistently lower proline contents than untreated plants under all UV exposure conditions, including under no UV stress, as further discussed in item "4".

Figure 01 :Figure 02 :
Figure 01: Effect of UVR regimen and/or mitigating Treatments on Malondialdehyde content.

Figure 03
Figure 03 data shows the average rates (1 to 5) of symptom response to stress from all assessments performed throughout the course of the trial.+UV-B radiation visually presents the highest level of damage to leaflets, whereas under +UV-A stress, leaflets visually present a lower response.Foliar treatment with the mineral composition is effective in mitigating most of the stress caused by both UV types, with treated leaves showing approximately 100% reduced visual damage compared to untreated under +UV-A exposure and 80% reduced visual damage under +UV-B exposure.Under +UV-A exposure, the visual effect is evidenced by a smaller leaf and a more rounded shape compared to a lanceolate type in the absence of UV exposure, whereas under +UV-B exposure, the leaf tissue tends to become crispy, and the portion of the leaflet close to its tip tends to bend slightly in a manner similar to boron deficiency (Figure 04).

Figure 03 :
Figure 03: Effect of UVR regimen and/or mitigating Treatments on the level of symptoms observed on the morphology of leaflets.
Exposure to UV radiation shows a remarkable negative effect on root development in untreated plants, as shown in the Figure 05 (C) and at the same time a strong attenuation of the effect when plants are treated with the composition.Plant roots under the +UV-B /untreated regimen shows the greatest negative impact, with minus 50% in dry weight, whereas when the aerial parts of the plant are treated, the level of impact is diminished by half (root weight impact being minus 24%).Under +UV-A / untreated, the impact also occurs, in the order of minus 27% root weight, whereas when leaves are treated, the impact is mitigated, showing only 6% weight reduction.Figure06shows pictures of the roots from treated and untreated plants under each of the tested UV regimens.

Figure 05 :
Figure 05: Effect of UVR regimen and/or Treatments on biometrics of (A) fresh weight of total leaflets per plant; (B) Number of pods per plant and (C) dry weight of roots per plant.
untreated leaflets, with greater mitigation shown under +UV-A exposure, which may indicate either that the composition is more effective in mitigating UV-A or that UV-B is indeed a much more stressful wavelenght, even though MDA reduction is significant in both exposure cases when plants are treated.The measurements of proline in the present study following exposure to +UV-A and +UV-B are in line with observations of other prior studies [14] on the effects of UV-A and UV-A/UV-B on soybean seedlings, which found a 25% lower content of proline in plants isolated from exposure to both UV-A and UV-A/UV-B.In our study, we observed both a proline response to UV regimens and a different response following foliar treatment, showing mitigation of the UV effect.Differently from MDA, proline content becomes progressively higher as the observed damage on plant biomass are also higher and following the respective level of effects of +UV-A or +UV-B.This is in conformity with well-established scientific documentation that proline accumulates in response to environmental stresses, and it can act as a signaling molecule to modulate mitochondrial functions, influence cell proliferation or cell death and trigger specific gene expression, which can be essential for plant recovery from stress [32].The accumulation of proline in response to UV-A, UV-B and UV-C occurs even in well-adapted desert plants acclimated under high levels of sunlight [28].An interesting finding in this study is the lower proline content in treated plants under all three UV regimen cases.For +UV-A and +UV-B cases, it is reasonable to infer that the composition applied over the top of plants formed a layer that prevented high levels of UV radiation from entering the leaves, thus not requiring the organism to increase proline for self-protection against this abiotic stress.For the no UV situation, we hypothesized that some other stress factor occurred simultaneously; possibly the fluctuation in soil moisture due to watering only once a day leading the leaves to experience variation in their turgor and, as the microparticles of quartz sand over the leaves preserve some leaf turgor (prior observation from authors, not published), such a change in a different concurring stress factor might have led to lower content of proline in treated plants in the no UV situation, which could also explain the slightly higher root weight of the no UV plants.The proline assay suggests that the foliar treatment mitigated the stress caused by +UV-A and +UV-B.

Figure 06 :
Figure 06: images of roots washed and dried, under trial treatments.

LegendsFigure 01 :
Figure 01: Effect of UVR regimen and/or mitigating treatments on malondialdehyde content.The graph shows the measurement results of four replications of each treatment.

Figure 02 :
Figure 02: Effect of UVR regimen and/or mitigating treatments on proline content.The graph shows the measurement results of four replications of each treatment.

Figure 03 :
Figure03: Effect of UVR regimen and/or mitigating treatments on morphology of leaflets.The graph shows the average of ratings given to the observed stress effect on leaflet in each treatment, being rate 1 as absence of observable symptom and 5 the highest level of stress observable.

Figure 04 :
Figure 04: Images of leaflets from trifoliate V4 under trial treatments.The size of each leaflet is out of comparable scale and shown for symptoms illustration only.The pictures are of one leaflet collected from the fourth trifoliate node (V4) from one replicate of each treatment that best represented the average of ratings and illustrates visually the effect of UV radiation and the mitigation treatment.Images comparing symptoms caused by UV-A, UV-B in contrast with absence of UV are rare in literature.Images were taken and edited by the author.

Figure 05 :
Figure 05: Effect of UVR regimen and/or mitigating treatments on biometrics of (A) fresh weight of total leaflets per plant; (B) number of pods per plant and (C) dry weight of roots per plant.The graph shows the measurement results of four replications of each treatment.

Figure 06 :
Figure 06: Images of roots washed and dried, under trial treatments.The image shows the roots of plants from each treatment, visually evidencing the impact of UV-A and UV-B radiation in reducing root volume and the mitigation treatment with the composition in attenuating this negative impact.Images of UV-A and UV-B effect over soybean roots at advanced plant development stages are rare in literature.Images were taken and edited by the author.