Lin Meng, Bacher Harel, Bourgault Richard, Qiao Pengfei, Matschi Susanne, Vasquez Miguel F, Mohammadi Marc, van Boerdonk Sarah, Scanlon Michael J, Smith Laurie G, Molina Isabel, Gore Michael A
Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA.
Department of Biology, Algoma University, Sault Ste. Marie, ON P6A 2G4, Canada.
G3 (Bethesda). 2024 Oct 10;14(12). doi: 10.1093/g3journal/jkae241.
Studying the genetic basis of leaf wax composition and its correlation with leaf cuticular conductance (gc) is crucial for improving crop productivity. The leaf cuticle, which comprises a cutin matrix and various waxes, functions as an extracellular hydrophobic layer, protecting against water loss upon stomatal closure. To address the limited understanding of genes associated with the natural variation of adult leaf cuticular waxes and their connection to gc, we conducted statistical genetic analyses using leaf transcriptomic, metabolomic, and physiological data sets collected from a maize (Zea mays L.) panel of ∼300 inbred lines. Through a random forest analysis with 60 cuticular wax traits, it was shown that high molecular weight wax esters play an important role in predicting gc. Integrating results from genome-wide and transcriptome-wide studies (GWAS and TWAS) via a Fisher's combined test revealed 231 candidate genes detected by all three association tests. Among these, 11 genes exhibit known or predicted roles in cuticle-related processes. Throughout the genome, multiple hotspots consisting of GWAS signals for several traits from one or more wax classes were discovered, identifying four additional plausible candidate genes and providing insights into the genetic basis of correlated wax traits. Establishing a partially shared genetic architecture, we identified 35 genes for both gc and at least one wax trait, with four considered plausible candidates. Our study enhances the understanding of how adult leaf cuticle wax composition relates to gc and implicates both known and novel candidate genes as potential targets for optimizing productivity in maize.
研究叶片蜡质成分的遗传基础及其与叶片角质层导度（gc）的相关性对于提高作物生产力至关重要。叶片角质层由角质基质和各种蜡质组成，作为细胞外疏水层，在气孔关闭时防止水分流失。为了解决对与成年叶片角质层蜡质自然变异相关的基因及其与gc的联系了解有限的问题，我们使用从约300个玉米自交系组成的群体中收集的叶片转录组、代谢组和生理数据集进行了统计遗传分析。通过对60个角质层蜡质性状的随机森林分析，结果表明高分子量蜡酯在预测gc方面起着重要作用。通过Fisher联合检验整合全基因组和转录组范围研究（GWAS和TWAS）的结果，发现所有三种关联检验都检测到231个候选基因。其中，11个基因在角质层相关过程中表现出已知或预测的作用。在整个基因组中，发现了多个由来自一个或多个蜡质类别的几个性状的GWAS信号组成的热点，确定了另外四个可能的候选基因，并为相关蜡质性状的遗传基础提供了见解。建立部分共享的遗传结构，我们确定了35个与gc和至少一个蜡质性状相关的基因，其中四个被认为是可能的候选基因。我们的研究增进了对成年叶片角质层蜡质成分与gc之间关系的理解，并暗示已知和新的候选基因是优化玉米生产力的潜在目标。
