COMMENTARY

Choice of both Ways: Variations of Reverted Repeats Balance Environmental Adaptation and Yield in Maize

Expand
  • 1Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2University of Chinese Academy of Sciences, Beijing 100049, China

Received date: 2022-04-29

  Accepted date: 2022-05-12

  Online published: 2022-11-25

Abstract

Optimal Balance between high yield and stress tolerance is the goal of breeding, which is related to the strategy in choice of both ways. The questions such as which negative regulators of stress tolerance affect yield and how they function are important issues for breeding. Over the past century, owing to the breeding of high-yield varieties, the maize yield has been tremendously increased, but this is accompanied with the increased sensitivity to environmental stresses, and the genetic mechanisms underlying this phenomenon remains elusive. This restricts the breeding of maize cultivars with both high yield and stress tolerance. Both yield traits and stress tolerance are complex quantitative traits, determined by the expression and regulation of a large number of genes. Small RNAs (sRNAs) are important gene expression regulators, and they are generated in large quantities from the maize genome. But the mechanisms underlying their regulation on crop stress responses and yield traits remain largely elusive. Recently, the group of Prof. Mingqiu Dai, collaborated with the groups of Prof. Lin Li and Prof. Feng Li at Huazhong Agricultural University, identified about ten-thousands of drought-responsive sRNAs and eQTLs associated with the expression of these sRNAs, by analyzing the sRNAome and transcriptome of a maize panel consisting 338 natural inbred lines grown under different environment conditions. They cloned an eQTL hotspot named DRESH8, which is a Transposable Element-mediated Inverted Repeat (TE-IR) in a length of about 21.4 kb. Genetic and molecular evidence showed that DRESH8-derived siRNAs directly inhibit the expression of the drought-resistant genes via a post-transcriptional silencing mechanism, and indirectly inhibit the expression of negative regulators of yield-related traits, thus negatively regulating drought response and positively regulate yield-related traits. Further analysis demonstrated that DRESH8 was selected during maize domestication and improvement. Their findings suggest that DRESH8 is a key genetic locus that balances maize yield and drought tolerance, and that IR-mediated balance between maize yield and drought resistance may be a universal mechanism. This study thus revealed a key genetic mechanism underlying balancing crop yield and environmental stress resistance at a genome-wide level, and provided a large number of valuable IR loci for breeding new maize varieties with both high yield and stress tolerance via genetic engineering approaches in the future.

Cite this article

Wang Lei, Chong Kang . Choice of both Ways: Variations of Reverted Repeats Balance Environmental Adaptation and Yield in Maize[J]. Chinese Bulletin of Botany, 2022 , 57(5) : 555 -558 . DOI: 10.11983/CBB22094

References

[1] Blein-Nicolas M, Negro SS, Balliau T, Welcker C, Cabrera-Bosquet L, Nicolas SD, Charcosset A, Zivy M (2020). A systems genetics approach reveals environ-ment-dependent associations between SNPs, protein co-expression, and drought-related traits in maize. Genome Res 30, 1593-1604.
[2] Jia JB, Ji RH, Li ZW, Yu YM, Nakano M, Long YP, Feng L, Qin C, Lu DD, Zhan JP, Xia R, Meyers BC, Liu B, Zhai JX (2020). Soybean DICER-LIKE2 regulates seed coat color via production of primary 22-nucleotide small interfering RNAs from long inverted repeats. Plant Cell 32, 3662-3673.
[3] Liu SX, Li CP, Wang HW, Wang SH, Yang SP, Liu XH, Yan JB, Li BL, Beatty M, Zastrow-Hayes G, Song SH, Qin F (2020). Mapping regulatory variants controlling gene expression in drought response and tolerance in maize. Genome Biol 21, 163.
[4] Sun XP, Xiang YL, Dou NN, Zhang H, Pei SR, Franco A, Menon M, Monier B, Ferebee T, Liu T, Liu SY, Gao YC, Wang JB, Terzaghi W, Yan JB, Hearne S, Li L, Li L, Dai MQ (2022). The role of transposon inverted repeats in balancing drought tolerance and yield-related traits in maize. Nat Biotechnol. Doi: https://www.nature.com/artic-les/s41587-022-01470-4
[5] Wu X, Feng H, Wu D, Yan SJ, Zhang P, Wang WB, Zhang J, Ye JL, Dai GX, Fan Y, Li WK, Song BX, Geng ZD, Yang WL, Chen GX, Qin F, Terzaghi W, Stitzer M, Li L, Xiong LZ, Yan JB, Buckler E, Yang WN, Dai MQ (2021). Using high-throughput multiple optical phenotyping to de-cipher the genetic architecture of maize drought toleran-ce. Genome Biol 22, 185.
[6] Zhang F, Wu JF, Sade N, Wu S, Egbaria A, Fernie AR, Yan JB, Qin F, Chen W, Brotman Y, Dai MQ (2021). Genomic basis underlying the metabolome-mediated drought adaptation of maize. Genome Biol 22, 260.
Outlines

/