Morphological and Biochemical Factors Associated with Constitutive Defense to Thrips in Alfalfa
Zhiqiang Zhang,
Qi Chen,
Rula Sa,
Rui Dai,
Shuang Shuang,
Xiaohong Jiang,
Huijie Liu,
Yao Tan,
Fang Tang,
Buhe Temuer
Affiliations
Zhiqiang Zhang
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Qi Chen
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Rula Sa
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Rui Dai
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Shuang Shuang
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Xiaohong Jiang
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Huijie Liu
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Yao Tan
College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010011, China
Fang Tang
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Buhe Temuer
Key Laboratory of Grassland Resources of the Ministry of Education, Technology Engineering Center of Drought and Cold-Resistant Grass Breeding in the North of the National Forestry and Grassland Administration, College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010010, China
Plants have evolved a series of inducible or constitutive defense mechanisms in response to herbivore attack. Constitutive plant defenses are morphological and biochemical traits of the plants themselves, regardless of the presence of herbivores. We bred an alfalfa variety (Caoyuan No.4) with high thrips resistance, but the mechanisms underlying Caoyuan No.4 resistance to thrips are not well understood. To explore the constitutive defense of Caoyuan No.4, the morphological and biochemical traits associated with constitutive defense to thrips in alfalfa were analyzed using a thrips-susceptible alfalfa accession (Caoyuan No.2) as a control. The results showed that Caoyuan No.4 had thicker palisade tissue and parenchyma tissue, wider collenchyma, phloem, cambium and lignin layer, and smaller epidermal cells and stomatal aperture compared to Caoyuan No.2. Moreover, Caoyuan No.4 showed more non-glandular trichomes in both leaves and stems, but less glandular trichomes and more wax in stems. In addition, the results of the widely targeted metabolomics analysis showed that metabolites related to flavonoid, isoflavonoid, flavone and flavonol biosynthesis, as well as cysteine and methionine metabolism, differed between CaoyuanNo.2 and Caoyuan No.4. These findings shed new light on the constitutive insect defense of plants associated with physical or biochemical traits and may provide convenient markers for breeding thrips-resistant alfalfa cultivars.
