Cell walls are basically complex with dynamic structures that are being involved in several growth and developmental processes, as well as responses to environmental stresses and the defense mechanism. Pectin is secreted into the cell wall in a highly methylesterified form. It is able to perform function after the de-methylesterification by pectin methylesterase (PME). Whereas, the pectin methylesterase inhibitor (PMEI) plays a key role in plant cell wall modification through inhibiting the PME activity. It provides pectin with different levels of degree of methylesterification to affect the cell wall structures and properties. The PME activity was analyzed in six tissues of Sorghum bicolor, and found a high level in the leaf and leaf sheath. PMEI families have been identified in many plant species. Here, a total of 55 pectin methylesterase inhibitor genes (PMEIs) were identified from S. bicolor whole genome, a more detailed annotation of this crop plant as compared to the previous study. Chromosomal localization, gene structures and sequence characterization of the PMEI family were analyzed. Moreover, cis-acting elements analysis revealed that each PMEI gene was regulated by both internal and environmental factors. The expression patterns of each PMEI gene were also clustered according to expression pattern analyzed in 47 tissues under different developmental stages. Furthermore, some SbPMEIs were induced when treated with hormonal and abiotic stress. Taken together, these results laid a strong foundation for further study of the functions of SbPMEIs and pectin modification during plant growth and stress responses of cereal.

(1) Background: As a halophytic species, Tamarix (Tamarix chinensis) can be used for saline soil rehabilitation in China. The reclamation and rehabilitation of saline soil depend on the water consumption of plants. However, whether water resources in saline soil can support the construction of Tamarix vegetation is still unknown. (2) Methods: In this study, we measured the transpiration (T) of Tamarix for 3 years using sap flow and the evaporation (E) for 1 year using a micro-lysimeter in Tamarix land. The evaporation values in 2016 and 2017 were estimated with the soil crop coefficients obtained in 2018. (3) Results: The evapotranspiration (ET) ranged from 514.2 to 573.8 mm and was greatly affected by the wind speed, VPD and groundwater table. Transpiration was the main form of water consumption in this region, accounting for 60.2% of the total evapotranspiration. Compared with bare land, vegetation construction increased soil moisture dissipation by 377.6 mm in 2018. According to on-site measurements and estimates, the water shortage in the dry year was 107.2 mm, and the residual water values in the normal year and wet year were 77.8 mm and 187.5 mm, respectively. May and September were months of widespread water shortages in different precipitation years. Although the cultivation of this plant increased water consumption, the groundwater table remained at approximately 0.5 m during the study year. (4) Conclusions: These results indicated that planting Tamarix in coastal saline soil was feasible for the reclamation and rehabilitation of saline soil. In the dry year (2017), the consumption of evapotranspiration exceeded the precipitation. The inverse occurred in the normal year (2016) and wet year (2018). Taken together, our findings showed that the water resources in the coastal saline soil of China could tolerate vegetation construction and laid a strong foundation for saline soil rehabilitation.

Irrigation and fertilization are the most effective measures to inhibit soil salt accumulation and increase yield of wheat (Triticum aestivum L.) grown in saline soils. The present study used a split‐plot experimental design with irrigation as the main plot and fertilizer application as the subplot from 2014 to 2016. The experiment had four levels each of irrigation (W0, no irrigation; W1, one irrigation; W2, two irrigations; W3, three irrigations) and fertilization (M, no fertilizer; Y, cow manure; W, chemical fertilizer; and H, 50% cow manure and 50% chemical fertilizer). The study identified sowing, jointing, and maturity as the major salt accumulation periods. After irrigation, the 0‐ to 20‐cm soil salinity during presowing, jointing, and grain filling decreased by 1.09, 0.28, 0.19 g kg⁻¹, and 0.76, 0.46, and 0.23 g kg⁻¹, from 2014 to 2016. The wheat roots were mainly distributed in the 0‐ to 30‐cm soil layer. Meanwhile, wheat evapotranspiration (ET) ranged from 153 to 402 and 202 to 451 mm from 2014 to 2016, respectively; and the ET under W3W were 2.62‐ and 2.23‐times higher than W0M. Additionally, W3W increased yield of wheat by 567.0 and 422.2% from 2014 to 2016, compared with W0M. Generally, the water use efficiency (WUE) decreases as irrigation increases; however, this study found no significant difference in WUE between W2 and W3. Meanwhile, the chemical fertilizer resulted in the highest WUE, 3.16‐ and 2.63‐times higher than no fertilizer. Thus, the study proposes W3W as a suitable treatment for wheat in the Yellow River Delta.