PGR

Roots

June 17, 2022 by Master, posted in AG-SAP, γ-PGA, PGR

Roots serve a vital role (among other functions) in extracting water from the soil, transporting it to the shoot and sustaining transpiration. To fulfill this function, roots have a complex anatomical structure consisting of different cell layers with varying hydraulic conductivities. This composite structure offers different pathways for radial flow of water from the root surface towards xylem vessels: (i) the apoplastic pathway through the intercellular space and the cell wall; (ii) the symplastic pathway via plasmodesmata channels extending across neighboring cells; and (iii) the transcellular pathway which involves crossing membranes of neighboring cells. Pathways (ii and iii) are commonly referred to as the cell-to-cell pathway.

Roots are capable of varying the permeability of their cells and tissues to fulfill multi-facet functions, such as (i) transport of water and nutrients towards the xylem vessels; (ii) protection against desiccation in drying soils; and (iii) avoidance of leakage of nutrients and photosynthesized compounds into the soil.

Products helps plants get better and stronger roots:

SAP

gamma-PGA

NAA

Mepiquat chloride for Cotton

May 12, 2022 by Master, posted in PGR

Mepiquat chloride is a plant growth regulator widely used in cotton (Gossypium hirsutum L.) production to suppress excessive vegetative growth, increase root growth and avoid yield losses.

To increase root growth, cotton seeds were treated with Mepiquat chloride to increase the number of lateral root (LRs) and improve drought resistance.

An increased indole-3-acetic acid (IAA) pool appeared to correlate with LR growth, and the principal source of IAA in germinating seeds is IAA conjugates.

PGR: Abscisic acid (ABA)

May 6, 2022May 6, 2022 by Master, posted in PGR, Uncategorized

Abscisic acid (ABA) is a plant hormone. ABA functions in many plant developmental processes, including seed and bud dormancy, the control of organ size and stomatal closure.

It is especially important for plants in the response to environmental stresses, including drought, soil salinity, cold tolerance, freezing tolerance, heat stress and heavy metal ion tolerance.

Functions
ABA was originally believed to be involved in abscission, which is how it received its name. This is now known to be the case only in a small number of plants. ABA-mediated signaling also plays an important part in plant responses to environmental stress and plant pathogens. The plant genes for ABA biosynthesis and sequence of the pathway have been elucidated. ABA is also produced by some plant pathogenic fungi via a biosynthetic route different from ABA biosynthesis in plants.

In preparation for winter, ABA is produced in terminal buds. This slows plant growth and directs leaf primordia to develop scales to protect the dormant buds during the cold season. ABA also inhibits the division of cells in the vascular cambium, adjusting to cold conditions in the winter by suspending primary and secondary growth.

Abscisic acid is also produced in the roots in response to decreased soil water potential (which is associated with dry soil) and other situations in which the plant may be under stress. ABA then translocates to the leaves, where it rapidly alters the osmotic potential of stomatal guard cells, causing them to shrink and stomata to close. The ABA-induced stomatal closure reduces transpiration (evaporation of water out of the stomata), thus preventing further water loss from the leaves in times of low water availability. A close linear correlation was found between the ABA content of the leaves and their conductance (stomatal resistance) on a leaf area basis.

Seed germination is inhibited by ABA in antagonism with gibberellin. ABA also prevents loss of seed dormancy.

Several ABA-mutant Arabidopsis thaliana plants have been identified and are available from the Nottingham Arabidopsis Stock Centre – both those deficient in ABA production and those with altered sensitivity to its action. Plants that are hypersensitive or insensitive to ABA show phenotypes in seed dormancy, germination, stomatal regulation, and some mutants show stunted growth and brown/yellow leaves. These mutants reflect the importance of ABA in seed germination and early embryo development.

Pyrabactin (a pyridyl containing ABA activator) is a naphthalene sulfonamide hypocotyl cell expansion inhibitor, which is an agonist of the seed ABA signaling pathway. It is the first agonist of the ABA pathway that is not structurally related to ABA.

Applications of PGR, 1-NAA and 1-NAA-Na

May 6, 2022May 6, 2022 by Master, posted in PGR

-NAA is a broad-spectrum-based plant growth regulator, can promote cell division and expansion, induced the formation of adventitious roots increased fruit set, preventing fruit drop, change female male flowers ratio. Via leaves and twigs of the tender skin and seeds into plants, the nutrient flow with the conduit to the whole plant.

-NAA reduce cotton ball falling, increasing fruit weight gain, improve quality. Promote flowering fruit trees, anti-fruit drop, ripening increase. Prevent fruits and vegetables from falling flowers, forming a small seed fruits; for rooting cuttings and other branches.

-NAA is widely used in agriculture, forestry, vegetable, flower, fruit etc. NAA can induce formation of adventitious root, improve cutting culture, promote fruit set, and prevent pre-maturation of fruit.

Mepiquat chloride for cotton

September 6, 2018 by Master, posted in PGR

Mepiquat chloride and mepiquat pentaborate both contain mepiquat which is an anti-gibberellin growth retardant that reduces plant cell enlargement to help balance vegetative and reproductive growth.

When applied to cotton, it can help control rank growth by reducing stem elongation at newly formed internodes.

The application of PGRs can help increase fruit retention and promote earlier maturity, reducing the crop’s risk of late-season insect damage, boll rots, and harvest losses.

Mepiquat applications have been linked to increased cotton yield potential when applied at the optimum rate and timing for the variety and field planted.

Effect of jasmonates on coloration and quality of the‘Christmas Rose’ grape berry

August 25, 2018 by Master, posted in PGR

Objective:

The‘Christmas Rose’grape is a type of the late-maturing cultivars which is widely planted in China. It is favored by consumers because of its delicate flesh，resistance to storage and transportation，and high quality. However，in some areas，the coloration of the‘Christmas Rose’grape was not very good because of high temperature and humidity，which affected its internal and external qualities. In recent years，researchers found that jasmonates，which widely exist in plants，could improve coloration of fruit by promoting the accumulation of anthocyanin. This study is to explain the effect of different concentrations of exogenous prohydrojasmon(PDJ)，methyl jasmonate(MeJA) on the coloration and quality of the‘Christmas Rose’grape so as to provide some theoretical evidence to improve coloration and quality of this grape berry.

Methods:

The trial was conducted at the experimental farm of the Zheng⁃zhou Fruit Research Institute，CAAS，on uniform 6- year- old‘Christmas Rose’grapevines. All treatments were applied in three replications and arranged in a complete randomized block design，with a single grapevine for each replication. Two different concentrations (10 mg·L– 1，50 mg·L– 1) of prohydrojasmon，methyl jasmonate were respectively applied to the‘Christmas Rose’grape berries. The aqueous solutions of both treatments and control involved 0.1% Tween-80 and 1% ethanol. The experimental grape berries were sprayed uniformly with aqueous solution twice at the beginning of veraison and 7 days later after the first application. After the first treatment，samples were taken every 10 days until the fruit was ripe when the seeds were completely brown and the soluble solids content no longer increased. A total of 40 single berries from the top，middle and bottom parts of randomly selected 10 grape bunches were picked and brought to the laboratory for analysis. The coloration of the grape berry was measured by a Minolta colorimeter and expressed as the L value (the fruit surface light brightness)，a value (color component of red and green)，b value (color component of yellow and blue) and CIRG value (color index of red grape). Anthocyanin content in the skin extraction was measured by the pH differential method. The contents of chlorophyll a and chlorophyll b in the skin extraction were tested according to the Arnon’s method. The soluble solids content of the fruit was measured by a PR-101 refractometer. The titratable acid in the grape juice was titrated by 0.1 mol·L– 1 NaOH according to the Gao’s method. The total phenolics，and flavonoids in the skin extraction were determined respectively according to the Jia and Meyer’s method. The pedicel endurable pulling force and berry endurable pressing force were measured by a Digital Push & Pull Tester. In addition，the berry weight，berry length，berry diameter，and the content of vitamin C were also determined. All analyses were performed using Excel and SPSS software.

Results:

During the ripening period of the grapes that were treated or not treated，the L value，and b value decreased，while the a value，and CIRG value increased，the brightness of the grape skin declined and the coloration of the grape skin was transformed from green to red. The grape berries treated with PDJ，and MeJA had a higher a value，CIRG value and a lower L value，b value than the control. The highest a value，CIRG value and the lowest L value，b value were found in the grapes treated with 50 mg·L-1 PDJ. At harvest，the CIRG value of 50 mg·L-1 PDJ-，MeJA- treated grapes reached 4.61 and 4.50 respectively while the CIRG value of the untreated grapes was only 4.04. During the ripening period of the grapes，the anthocyanin content rose gradually，in contrast to chlorophyll a and chlorophyll b which declined gradually in the grape skin. The content of anthocyanin in the grape skin treated with PDJ，and MeJA was obviously higher than the control. The 50 mg·L-1 PDJ，and MeJA treated grapes presented a higher an⁃ thocyanin content than the 10 mg·L-1 PDJ，and MeJA- treated grapes. The PDJ treatment had a better effect than the MeJA treatment under the same concentration on increasing the content of anthocyanin. At harvest，the anthocyanin content in the grape skin treated with 50 mg·L-1 PDJ，and 50 mg·L-1 MeJA was respectively 31.2%，and 20.0% higher than the control. The content of chlorophyll a and chlorophyll b in the grape skins treated with PDJ，and MeJA were lower compared with the control. The PDJ，and MeJA treatments promoted the synthesis of anthocyanin while enhanced the degradation of chlorophyll a and chlorophyll b，and the coloration of the grape berry improved. The 50 mg·L– 1 PDJ treatment performed best in improving the coloration of the grape berries among all of the treatments. During the period of maturation，the soluble solids content of grapes treated with PDJ，and MeJA were obviously higher compared with the grapes that were untreated. The 50 mg·L-1 PDJ，and MeJA treatments were more effective in increasing the content of soluble solids than the 10 mg·L-1 PDJ，and MeJA treatments. There were no obvious differences between the treated and untreated grapes on the titratable acid content. The application of PDJ，and MeJA promoted the accumulation of total phenolics，and flavonoids in the skin at harvest，and total phenolics in the skin treated with 50 mg·L-1 PDJ，and MeJA were respectively 36.4%，and 29.0% higher than the control. The application of PDJ，and MeJA significantly enhanced the content of vitamin C in the fruit，however，the berry weight，berry length and berry diameter were not influenced. The grape treated with PDJ，and MeJA had a higher nutritional quality，in addition，the PDJ，and MeJA treatment did not have a negative effect on fruit yield. The pedicel endurable pulling force and berry endurable pressing force were not influenced by the PDJ，and MeJA treatment. The phenomenon of berry drop did not happen in the treated grapes. There was no difference between the treated and untreated grapes on resistance to storage and transportation.

Conclusion:

Two different concentrations of exogenous PDJ，and MeJA improved coloration and quality of the‘Christmas Rose’grape berry compared with the control. Under the same concentration，the PDJ treatment had a better effect than the MeJA treatment on improving coloration and the quality of grapes; the 50 mg·L-1 PDJ，and MeJA treatment showed a better effect than the 10 mg·L-1 PDJ，and MeJA treatment. Among all of the treatments，the 50 mg·L-1 PDJ treatment was the most effective in improving the coloration and quality of grapes in the trial.