Efficacy of Root Zone Temperature Increase in Root and Shoot Development and Hormone Changes in Different Maize Genotypes

In the context of global warming, the effects of warming in the root zone of crops on maize seedling characteristics deserve research attention. Previous studies on the adaptive traits of dryland maize have mainly focused on soil moisture and nutrients, rather than analyzing potential factors for the adaptive traits of root zone warming. This study was conducted to investigate the effects of different root zone warming ranges on the agronomic traits, hormones, and microstructures of maize seedling roots and leaves. The results showed that minor increases in the root zone temperature significantly enhanced maize seedling growth. However, when the temperature in the root zone was excessive, the stem diameter, root surface area, root volume, total root length, dry matter accumulation, and root/shoot biomass of maize seedlings sharply decreased. Under high temperature stress in the root zone, the root conduit area; root stele diameter; root content of trans-zeatin (ZT), gibberellin A3 (GA3), and indoleacetic acid (IAA); leaf thickness; upper and lower epidermis thickness; and leaf content of ZT and GA3 were significantly decreased. The hormone content and microstructure changes might be an important reason for root growth maldevelopment and nutrient absorption blockage, and they also affected the leaf growth of maize seedlings. Compared with the ‘senescent’ maize type Shaandan 902 (SD902), the plant microstructure of the ‘stay-green’ maize type Shaandan 609 (SD609) was less affected by increased temperatures, and the ability of the root system to absorb and transport water was stronger, which might explain its tolerance of high temperature stress in the root zone.

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Effects of Root Zone Warming on Maize Seedling Growth and Photosynthetic Characteristics Under Different Phosphorus Levels

Frontiers in Plant Science ◽

10.3389/fpls.2021.746152 ◽

2021 ◽

Vol 12 ◽

Author(s):

Zhenqing Xia ◽

Shibo Zhang ◽

Qi Wang ◽

Guixin Zhang ◽

Yafang Fu ◽

...

Keyword(s):

High Temperature ◽

Phosphorus Content ◽

Root Zone ◽

Phosphorus Deficiency ◽

Temperature Treatment ◽

Maize Seedlings ◽

Medium Temperature ◽

Root Zone Temperature ◽

Low Phosphorus ◽

Zone Temperature

Phosphorus content and root zone temperature are two major environmental factors affecting maize growth. Both low phosphorus and root zone high temperature stress significantly affect the growth of maize, but the comprehensive effects of phosphorus deficiency and root zone warming are less studied. This study aimed to explore the effects of phosphorus deficiency and root zone warming on the root absorption capacity, total phosphorus content, and photosynthetic fluorescence parameters of maize seedlings. The results showed that maize shoots and roots had different responses to root zone warming and phosphorus deficiency. Properly increasing the root zone temperature was beneficial to the growth of maize seedlings, but when the root zone temperature was too high, it significantly affected the root and shoot development of maize seedlings. The root zone warming had a more significant impact on the root system, while phosphorus deficiency had a greater impact on the shoots. Phosphorus content and root zone warming had a strong interaction. Under the comprehensive influence of normal phosphorus supply and medium temperature in the root zone, the growth of maize seedlings was the best. Under the combined effects of low phosphorus and high temperature in the root zone, the growth was the worst. Compared with the combination of normal phosphorus and root zone medium temperature treatment, the dry mass of the low-phosphorus root zone high temperature treatment was decreased by 55.80%. Under the condition of low-phosphorus too high root zone temperature reduced root vitality, plant phosphorus content, which in turn affected plant growth and light energy utilization efficiency. In the case of sufficient phosphate fertilizer supply, appropriately increasing the soil temperature in the root zone is beneficial to increase the absorption and utilization of phosphorus by plants and promote the growth and development of maize seedlings.

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The effects of low root-zone temperature stress on two soybean (Glycine max) genotypes when combined with Bradyrhizobium strains of varying geographic origin

Physiologia Plantarum ◽

10.1034/j.1399-3054.1994.900116.x ◽

1994 ◽

Vol 90 (1) ◽

pp. 105-113 ◽

Cited By ~ 2

Author(s):

D. H. Lynch ◽

D. L. Smith

Keyword(s):

Glycine Max ◽

Temperature Stress ◽

Root Zone ◽

Geographic Origin ◽

Root Zone Temperature ◽

Low Root Zone Temperature ◽

Zone Temperature

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Effects of Root Zone Temperature on Root Activity of Two Potato (Solanum tuberosum L.) Clones with Different Adaptation to High Temperature

Journal of Agronomy and Crop Science ◽

10.1111/j.1439-037x.1990.tb00843.x ◽

1990 ◽

Vol 165 (2-3) ◽

pp. 131-137 ◽

Cited By ~ 12

Author(s):

B. Sattelmacher ◽

H. Marschner ◽

R. Kühne

Keyword(s):

Solanum Tuberosum ◽

High Temperature ◽

Root Zone ◽

Solanum Tuberosum L ◽

Root Activity ◽

Root Zone Temperature ◽

Zone Temperature

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High Soil Temperature and Water Relations of Endomycorrhizal Nursery Crops2

Journal of Environmental Horticulture ◽

10.24266/0738-2898-5.2.93 ◽

1987 ◽

Vol 5 (2) ◽

pp. 93-96

Author(s):

Steven E. Newman ◽

Fred T. Davies

Keyword(s):

High Temperature ◽

Stomatal Conductance ◽

Soil Temperature ◽

Water Potential ◽

Stress Tolerance ◽

Root Zone ◽

Root Zone Temperature ◽

Root Conductance ◽

High Soil Temperature ◽

Zone Temperature

High root-zone temperatures can stress plants and reduce nursery productivity of container-grown crops. Predawn shoot water potential was initially increased (less water strain) by root-zone temperatures from 40° to 45°C (104° to 113 °F) and then subsequently declined after 3 days. Stomatal conductance (SC) was reduced at similar root-zone temperatures. Hydraulic root conductance (Lp) increased linearly in response to increasing root-zone temperatures for high temperature tolerant species, and quadratically for susceptible species. Endomycorrhizal fungi colonization enhanced high root-zone temperature stress tolerance at moderate temperatures from 35 ° to 40°C (95 ° to 104°F).

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Growth of Honey Locust Seedlings during High Root-zone Temperature and Osmotic Stress

HortScience ◽

10.21273/hortsci.26.10.1312 ◽

1991 ◽

Vol 26 (10) ◽

pp. 1312-1315 ◽

Cited By ~ 3

Author(s):

William R. Graves ◽

Lorna C. Wilkins

Keyword(s):

Polyethylene Glycol ◽

High Temperature ◽

Root Zone ◽

Temperature Treatment ◽

Root Zone Temperature ◽

Temperature Regimes ◽

Honey Locust ◽

Effects Of Temperature ◽

Peg 8000 ◽

Zone Temperature

Growth of honey locust (Gleditsia triacanthos var. inermis Willd.) seedlings was studied during exposure to reduced osmotic potential (ψπ) and high temperature in the root zone. Half-sib plants were cultured in solution. Root-zone temperature was increased from ambient (23C) to 35C for 0, 6, 12, or 24 hours·day -l. Within each temperature treatment, solution ψπ of -0.05, – 0.10, and – 0.20 MPa were maintained by additions of polyethylene glycol (PEG) 8000. Root and shoot dry weights decreased with increasing exposure to 35C among seedlings in -0.05-MPa solution and decreased for seedlings in - 0.10- and - 0.20-MPa solutions in all temperature regimes. Growth of epicotyls displayed similar trends, but epicotyls of plants in -0.20-MPa solution were longest with 6 hours·day-l at 35C. Significant interactions between effects of temperature and osmotic regimes indicated that water-stressed honey locust seedlings are relatively insensitive to elevated root-zone temperatures. However, related studies showed that PEG caused reductions in growth that could not be explained by decreases in ψπ and suggested that responses of honey locust to PEG differed from those when drought was imposed by withholding irrigation in an aggregate medium.

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The effects of low root-zone temperature stress on two soybean (Glycine max) genotypes when combined with Bradyrhizobium strains of varying geographic origin

Physiologia Plantarum ◽

10.1111/j.1399-3054.1994.tb02199.x ◽

1994 ◽

Vol 90 (1) ◽

pp. 105-113 ◽

Cited By ~ 20

Author(s):

D. H. Lynch ◽

D. L. Smith

Keyword(s):

Glycine Max ◽

Temperature Stress ◽

Root Zone ◽

Geographic Origin ◽

Root Zone Temperature ◽

Low Root Zone Temperature ◽

Zone Temperature

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Daily temperature extremes as an indicator of high temperature stress

Soil Research ◽

10.1071/sr9910377 ◽

1991 ◽

Vol 29 (3) ◽

pp. 377 ◽

Cited By ~ 6

Author(s):

KL Bristow ◽

DG Abrecht

Keyword(s):

High Temperature ◽

Temperature Stress ◽

High Temperature Stress ◽

Shoot Length ◽

General Relationship ◽

Daily Temperature ◽

Temperature Extremes ◽

Maize Seedlings ◽

Stress Application ◽

Time Of Year

Theory outlining a general relationship between stress experienced by an organism exposed to supra-optimal temperatures and daily temperature extremes is discussed. It is shown that useful nomograms relating Tmax, Tmin, Tcritical, and high temperature stress can be developed and that these nomograms are not particularly sensitive to changes in daylength (caused by changes in time of year or latitude). Sensitivity of high temperature stress to changes in Tmin is also considerably less than that to changes in Tmax, suggesting that in situations where Tmin, does not vary greatly, Tmax alone can be used as an indicator of high temperature stress. Application of these concepts is illustrated by analyses of high temperature stress in pre-emergent maize seedlings. Results show that Tmax alone can account for more than 90% of the variation in the reduction of shoot length due to the occurrence of supra-optimal temperatures.

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