Spatial distribution of transcript changes in the maize primary root elongation zone at low water potential

AbstractThe gaseous hormone ethylene participates in many physiological processes of plants. It is well known that ethylene-inhibited root elongation involves basipetal auxin delivery requiring PIN2. However, the molecular mechanism how ethylene regulates PIN2 is not well understood. Here, we report that the ethylene-responsive HD-Zip gene HB52 is involved in ethylene-mediated inhibition of primary root elongation. Using biochemical and genetic analyses, we demonstrated that HB52 is ethylene-responsive and acts immediately downstream of EIN3. HB52 knock-down mutants are insensitive to ethylene in primary root elongation while the overexpression lines have dramatically shortened roots like ethylene treated plants. Moreover, HB52 upregulates PIN2, WAG1, and WAG2 by directly binding to their promoter, leading to an enhanced basipetal auxin delivery to the elongation zone and thus inhibiting root growth. Our work uncovers HB52 as an important crosstalk node between ethylene signaling and auxin transport in root elongation.

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Primary Root Elongation Rate and Abscisic Acid Levels of Maize in Response to Water Stress

Crop Science ◽

10.2135/cropsci2009.12.0708 ◽

2011 ◽

Vol 51 (1) ◽

pp. 157-172 ◽

Cited By ~ 16

Author(s):

Kristen A. Leach ◽

Lindsey G. Hejlek ◽

Leonard B. Hearne ◽

Henry T. Nguyen ◽

Robert E. Sharp ◽

...

Keyword(s):

Abscisic Acid ◽

Water Stress ◽

Root Elongation ◽

Primary Root ◽

Elongation Rate ◽

Root Elongation Rate ◽

Response To Water

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Two Expansin Genes, AtEXPA4 and AtEXPB5, Are Redundantly Required for Pollen Tube Growth and AtEXPA4 Is Involved in Primary Root Elongation in Arabidopsis thaliana

Genes ◽

10.3390/genes12020249 ◽

2021 ◽

Vol 12 (2) ◽

pp. 249

Author(s):

Weimiao Liu ◽

Liai Xu ◽

Hui Lin ◽

Jiashu Cao

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Cell Walls ◽

Root Elongation ◽

Expression Patterns ◽

Primary Root ◽

Pollen Grains ◽

Tube Growth ◽

Cell Wall Binding

The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.

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The bacterial volatile N,N-dimethyl-hexadecylamine promotes Arabidopsis primary root elongation through cytokinin signaling and the AHK2 receptor

Plant Signaling & Behavior ◽

10.1080/15592324.2021.1879542 ◽

2021 ◽

Vol 16 (4) ◽

pp. 1879542

Author(s):

Ernesto Vázquez-Chimalhua ◽

Salvador Barrera-Ortiz ◽

Eduardo Valencia-Cantero ◽

José López-Bucio ◽

León Francisco Ruiz-Herrera

Keyword(s):

Root Elongation ◽

Primary Root ◽

Cytokinin Signaling

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The Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE 1 Gene Is Involved in Anisotropic Root Growth during Osmotic Stress Adaptation

Genes ◽

10.3390/genes12020236 ◽

2021 ◽

Vol 12 (2) ◽

pp. 236

Author(s):

María Belén Cuadrado-Pedetti ◽

Inés Rauschert ◽

María Martha Sainz ◽

Vítor Amorim-Silva ◽

Miguel Angel Botella ◽

...

Keyword(s):

Osmotic Stress ◽

Root Growth ◽

Cell Walls ◽

Primary Root ◽

Stress Adaptation ◽

Elongation Zone ◽

Cortical Cells ◽

Force Microscopy ◽

Atomic Force ◽

The Mean

Mutations in the Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE 1 (TTL1) gene cause reduced tolerance to osmotic stress evidenced by an arrest in root growth and root swelling, which makes it an interesting model to explore how root growth is controlled under stress conditions. We found that osmotic stress reduced the growth rate of the primary root by inhibiting the cell elongation in the elongation zone followed by a reduction in the number of cortical cells in the proximal meristem. We then studied the stiffness of epidermal cell walls in the root elongation zone of ttl1 mutants under osmotic stress using atomic force microscopy. In plants grown in control conditions, the mean apparent elastic modulus was 448% higher for live Col-0 cell walls than for ttl1 (88.1 ± 2.8 vs. 16.08 ± 6.9 kPa). Seven days of osmotic stress caused an increase in the stiffness in the cell wall of the cells from the elongation zone of 87% and 84% for Col-0 and ttl1, respectively. These findings suggest that TTL1 may play a role controlling cell expansion orientation during root growth, necessary for osmotic stress adaptation.

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Early Pinus caribaea var. hondurensis root development. 2. Influence of soil strength

Australian Journal of Experimental Agriculture ◽

10.1071/ea9960847 ◽

1996 ◽

Vol 36 (7) ◽

pp. 847 ◽

Cited By ~ 8

Author(s):

A Costantini ◽

D Doley ◽

HB So

Keyword(s):

Root Development ◽

Soil Type ◽

Root Elongation ◽

Primary Root ◽

High Strength ◽

Soil Strength ◽

Shoot Development ◽

Pinus Caribaea ◽

Primary Shoot ◽

Primary Roots

The influence of penetration resistance (PR), an easily measured indicator of soil strength, on the growth of Pinus caribaea var. hondurensis radicles and seedlings was investigated. Negative exponential relationships between PR and both radicle and primary root elongation were observed. All root elongation ceased at PR levels of 3.25 MPa. Tip diameters of radicles and primary roots were positively correlated with PR values up to 2.4 MPa, whilst numbers of primary roots, total root lengths and lengths of longest roots were all negatively correlated with PR. Hypocotyl elongation was also reduced by increasing PR, although the reductions occurred at higher PRs than those which inhibited root development. In contrast, primary shoot development was unaffected by PR levels which were sufficient to stop root elongation, but was reduced in soil with a PR of 4.8 MPa. There were significant family x soil type and family x PR interactions for radicle, hypocotyl, primary root and primary shoot development. 1f these interactions are correlated with performance in the field, then they may serve as useful indicators of family suitability to both soil type and high strength soils.

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