Root pruning improves maize water-use efficiency by root water absorption

Minfei Yan; Cong Zhang; Hongbing Li; Li Zhang; Yuanyuan Ren; Yinglong Chen; Huanjie Cai; Suiqi Zhang

doi:10.3389/fpls.2022.1023088

Root pruning improves maize water-use efficiency by root water absorption

Front Plant Sci. 2023 Jan 4:13:1023088. doi: 10.3389/fpls.2022.1023088. eCollection 2022.

Authors

Minfei Yan^{1

2}, Cong Zhang^{1

2}, Hongbing Li¹, Li Zhang³, Yuanyuan Ren⁴, Yinglong Chen^{1

5}, Huanjie Cai⁶, Suiqi Zhang¹

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China.
² College of Forestry, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China.
³ School of Pharmacy, Weifang Medical University, Weifang, China.
⁴ Geography and Environmental Engineering Department, Baoji University of Arts and Sciences, Baoji, China.
⁵ The University of Western Australia Institute of Agriculture, and University of Western Australia School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia.
⁶ Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest Agriculture and Forestry University, Yangling, China.

Abstract

Root systems are an important component of plants that impact crop water-use efficiency (WUE) and yield. This study examined the effects of root pruning on maize yield, WUE, and water uptake under pot and hydroponic conditions. The pot experiment showed that root pruning significantly decreased root/shoot ratio. Both small root pruning (cut off about 1/5 of the root system, RP1) and large root pruning (cut off about 1/3 of the root system, RP2) improved WUE and root hydraulic conductivity (Lpr) in the residual root system. Compared with that in the un-cut control, at the jointing stage, RP1 and RP2 increased Lpr by 43.9% and 31.5% under well-watered conditions and 27.4% and 19.8% under drought stress, respectively. RP1 increased grain yield by 12.9% compared with that in the control under well-watered conditions, whereas both pruning treatments did not exhibit a significant effect on yield under drought stress. The hydroponic experiment demonstrated that root pruning did not reduce leaf water potential but increased residual root hydraulic conductivity by 26.2% at 48 h after root pruning under well-watered conditions. The foregoing responses may be explained by the upregulation of plasma membrane intrinsic protein gene and increases in abscisic acid and jasmonic acid in roots. Increased auxin and salicylic acid contributed to the compensated lateral root growth. In conclusion, root pruning improved WUE in maize by root water uptake.

Keywords: abscisic acid; jasmonic acid; leaf water potential; root hydraulic conductivity; root pruning.