Sexual Differences in Physiological and Transcriptional Responses to Salinity Stress of Salix linearistipularis

Abstract

Willow (Salix), a dioecious plant, is an important ornamental tree species in the world. Salix linearistipularis, a perennial woody plant species naturally distributed on the Songnen Plain saline-alkali land in northeast China, has a high saline condition. To study the sexual differences of S. linearistipularis in salinity tolerance, the physiological and transcriptional responses to salinity were compared between female and male cuttings. Under salinity stress, the female leaves exhibited higher superoxide dismutase and peroxidase activities and photosynthetic capacity, and lower H 2 O 2 contents than those of male leaves. Under salinity stress, sodium (Na +) accumulation in female leaves was lower than that in the male leaves. The non-invasive micro-test showed that the net Na + efflux in the salt-treated female roots was higher than that in male roots. Physiological responses revealed that female cuttings were more tolerant than males, which may be mainly due to females having lower leaf Na + accumulation and higher root Na + efflux capacity than males. Transcriptional analyses showed that 108 differentially expressed salt-responsive genes were identified in both female and male roots; most of these showed sexual differences in expression patterns under salinity stress. RNAseq combined with qPCR analysis showed that the salt-induced expression of four Na + /H + antiporter (NHX) genes (SlNHX3, 5, 6, 7) in female roots was higher than that in male roots. Transcriptional analyses revealed that the higher Na + efflux capacity in female roots than in male roots may be closely related to the differential expression of salt-responsive genes, especially NHX genes.

Ion absorption, distribution and salt tolerance threshold of three willow species under salt stress

“…Regarding the salt tolerance of willow, studies have mostly focused on root vigor, growth, salt tolerance, plant phenotype, physiological substances, and molecular biology. They observed a series of phenomena under salt stress, including root activity, plant growth index, and plant height decrease with increasing stress ( Sui, 2006 ; Markus-Michalczyk et al, 2014 ; Tian and Li, 2018 ; Feng et al, 2020 ; Zhang et al, 2021 ). However, studies on the salt distribution on plant roots and leaves and salt tolerance thresholds are still not in-depth and systematic ( Maggio et al, 2007 ; Kurunc et al, 2020 ; Banakar et al, 2022 ).…”

Gender Discrimination of Flower Buds of Mature Populus tomentosa by HPLC Fingerprint Combined with Chemometrics

“…P. tomentosa is one of the dioecious plants that refers to seed plants with unisexual flowers and where the female and male flowers grow on different plants [ 14 , 15 ]. In the last several years, many studies have focused mainly on physiological and biochemical indicators [ 16 , 17 ] and molecular biotechnology [ 18 , 19 ]. However, few studies have compared the differences between dioecious plants from the perspective of chemical constituents and their content [ 20 ].…”

Characterization of the complete chloroplast genome of Salix linearistipularis (Franch.) Hao 1936

“…Thus, it is broadly used for landscaping, alkali soil improvement, sand fixation, and reforestation with high ecological and economic benefits (Nan et al 2016 ). Furthermore, the identification of genes for stress tolerance in this dioecious plant can facilitate the study of sex differentiation (a.Feng et al 2020 ) and sex-related salt tolerance mechanisms (b.Feng et al 2020 ). Nevertheless, due to the highly efficient crossing rate among Salix species, the classification of the genus Salix spp.…”