Jalal Arshad, Oliveira Carlos Eduardo da Silva, Bastos Andréa de Castro, Fernandes Guilherme Carlos, de Lima Bruno Horschut, Furlani Junior Enes, de Carvalho Pedro Henrique Gomes, Galindo Fernando Shintate, Gato Isabela Martins Bueno, Teixeira Filho Marcelo Carvalho Minhoto
Department of Plant Protection, Rural Engineering and Soils (DEFERS), São Paulo State University (UNESP), Ilha Solteira, Brazil.
Department of Plant Science, Food Technology and Socio-Economics, São Paulo State University (UNESP), Ilha Solteira, Brazil.
Front Plant Sci. 2023 Jan 12;13:1046642. doi: 10.3389/fpls.2022.1046642. eCollection 2022.
Plant growth-promoting bacteria (PGPBs) could be developed as a sustainable strategy to promote plant growth and yield to feed the ever-growing global population with nutritious food. Foliar application of nano-zinc oxide (ZnO) is an environmentally safe strategy that alleviates zinc (Zn) malnutrition by improving biochemical attributes and storage proteins of grain.
In this context, the current study aimed to investigate the combined effect of seed inoculation with PGPBs and foliar nano-ZnO application on the growth, biochemical attributes, nutrient metabolism, and yield of maize in the tropical savannah of Brazil. The treatments consisted of four PGPB inoculations [i.e., without inoculation () () (), which was applied on the seeds] and two doses of Zn (i.e., 0 and 3 kg ha, applied from nano-ZnO in two splits on the leaf).
Inoculation of with foliar ZnO application increased shoot dry matter (7.3 and 9.8%) and grain yield (17.1 and 16.7%) in 2019-20 and 2020-2021 crop seasons respectively. Inoculation with A. brasilense increased 100-grains weight by 9.5% in both crop seasons. Shoot Zn accumulation was improved by 30 and 51% with inoculation of P. fluorescens in 2019-20 and 2020-2021 crop seasons. Whereas grain Zn accumulation was improved by 49 and 50.7% with inoculation of and P. fluorescens respectively. In addition, biochemical attributes (chlorophyll a, b and total, carotenoids, total soluble sugar and amino acids) were improved with inoculation of along with foliar nano ZnO application as compared to other treatments. Co-application of P. fluorescens with foliar ZnO improved concentration of grains albumin (20 and 13%) and globulin (39 and 30%). Also, co-application of and foliar ZnO improved concentration of grains glutelin (8.8 and 8.7%) and prolamin (15 and 21%) in first and second seasons.
Therefore, inoculation of and with foliar nano-ZnO application is considered a sustainable and environmentally safe strategy for improving the biochemical, metabolic, nutritional, and productivity attributes of maize in tropical Savannah regions.
植物促生细菌（PGPBs）可被开发为一种可持续战略，以促进植物生长和提高产量，从而为不断增长的全球人口提供营养丰富的食物。叶面喷施纳米氧化锌（ZnO）是一种环境安全的策略，可通过改善谷物的生化特性和贮藏蛋白来缓解锌（Zn）营养不良。
在此背景下，本研究旨在探讨接种PGPBs种子并叶面喷施纳米ZnO对巴西热带稀树草原地区玉米生长、生化特性、养分代谢和产量的综合影响。处理包括四种PGPB接种（即不接种（）（）（），应用于种子）和两种锌剂量（即0和3 kg/公顷，分两次从纳米ZnO喷施在叶片上）。
2019 - 2020年和2020 - 2021年作物季，接种并叶面喷施ZnO分别使地上部干物质增加7.3%和9.8%，籽粒产量增加17.1%和16.7%。在两个作物季中，接种巴西固氮螺菌使百粒重增加9.5%。2019 - 2020年和2020 - 2021年作物季，接种荧光假单胞菌分别使地上部锌积累量提高30%和51%。而接种巴西固氮螺菌和荧光假单胞菌分别使籽粒锌积累量提高49%和50.7%。此外，与其他处理相比，接种巴西固氮螺菌并叶面喷施纳米ZnO可改善生化特性（叶绿素a、b和总量、类胡萝卜素、总可溶性糖和氨基酸）。荧光假单胞菌与叶面ZnO共同施用提高了籽粒白蛋白（20%和13%）和球蛋白（39%和30%）的浓度。在第一季和第二季中，巴西固氮螺菌与叶面ZnO共同施用还提高了籽粒谷蛋白（8.8%和8.7%）和醇溶蛋白（15%和21%）的浓度。
因此，接种巴西固氮螺菌和荧光假单胞菌并叶面喷施纳米ZnO被认为是一种可持续且环境安全的策略，可改善热带稀树草原地区玉米的生化、代谢、营养和生产力特性。
