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Theoretically, the PEP-CK C4 subtype has a higher quantum yield of CO2 assimilation than NADP-ME or NAD-ME subtypes because ATP required for operating the CO2-concentrating mechanism is believed to mostly come from the mitochondrial electron transport chain (mETC). However, reportedis not higher in PEP-CK than in the other subtypes. We hypothesise, more photorespiration, associated with higher leakiness and O2 evolution in bundle-sheath (BS) cells, cancels out energetic advantages in PEP-CK species.Nine species (two to four species per subtype) were evaluated by gas exchange, chlorophyll fluorescence, and two-photon microscopy to estimate the BS conductance (gbs) and leakiness using a biochemical model.Average gbs estimates were 2.9, 4.8, and 5.0 mmol m−2 s−1 bar−1, and leakiness values were 0.129, 0.179, and 0.180, in NADP-ME, NAD-ME, and PEP-CK species, respectively. The BS CO2 level was somewhat higher, O2 level was marginally lower, and thus, photorespiratory loss was slightly lower, in NADP-ME than in NAD-ME and PEP-CK species. Differences in these parameters existed among species within a subtype, and gbs was co-determined by biochemical decarboxylating sites and anatomical characteristics.Our hypothesis and results partially explain variations in observed, but suggest that PEP-CK species probably use less ATP from mETC than classically defined PEP-CK mechanisms.

Yang He,1 Wenjing Ouyang,2 Zhenzhen Li,3 Baojian Wei4 1School of Business, Xiangtan University, Xiangtan, 411105, People’s Republic of China; 2Department of Business School, Hunan Normal University, Changsha, 410081, People’s Republic of China; 3Taylor’s University, Subang Jaya, 47500, Malaysia; 4School of Nursing, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, 271021, People’s Republic of ChinaCorrespondence: Baojian Wei, Changcheng Road, Beijipo Street, Daiyue District, Taian City, People’s Republic of China, Tel +86-15564848382, Email bjwei@sdfmu.edu.cnPurpose: Given the increasing longevity of the population, the consolidation of familial structures, and the scarcity of economic resources required to sustain an aging society, the Chinese government faces a complex and urgent challenge in effectively addressing the growing needs of older adults and establishing a long-term care services system that is both sustainable and equitable.Patients and Methods: This study harnesses the comprehensive CLHLS data from 2011 to 2018 and utilizes the “Pilot Industrialization of Old-Age Service in a Market-Oriented Way” policy as a quasi-natural experiment. Employing the Difference-in-Differences (DID) method, our study aims to evaluate the impact of industrializing older adult care services on the physical and mental health outcomes of older adults in China.Results: The findings strongly indicate that the government’s adoption of a market-driven fiscal approach within its policies, aimed at attracting social capital and fostering the industrialization of older adult care services, positively influences the physical and mental well-being of the aged population. Furthermore, through heterogeneity analysis, it becomes evident that the health promotion effect is particularly pronounced among older individuals living without a spouse, lacking family care from children or grandchildren, or residing in financially underdeveloped r

Increasing fresh water scarcity is a major constraint for rice (Oryza sativa) productivity under future climatic conditions. It is important to understand why rice cannot perform like other dryland cereals, when grown under drier soil conditions. The responses of plant growth, plant water status, leaf and stem anatomical attributes to soil water deficit were examined at two developmental stages of three rice and two wheat (Triticum aestivum) cultivars grown under three water regimes in a pot experiment. Yield and yield components were determined at plant maturity. The stress sensitivity of plant growth was slightly more prominent at vegetative than at flowering stages. Water deficit limited root growth but had little impact on above-ground growth in rice plants. The xylem system of the leaves was more developed in rice than in wheat, but the opposite was true for the root xylem system. Compared with stem xylem attributes, leaf xylem attributes played a larger role in modulating leaf water potential under water deficit. In addition, the variation in yield response to water deficit between various types of rice, and between rice and wheat was closely associated with the response of leaf water potential to water deficit. To grow rice in drier conditions, its xylem system should be balanced by increasing root growth and modifying leaf anatomy.

Rice (Oryza sativa) is one of the most important cereal crops with high economic and social values. Natural diversity in water-deficit tolerance has allowed rice genotypes to adapt to different edaphic conditions. While genotypes adapted to the irrigated lowland system are most productive, the growing scarcity of freshwater resources for agriculture calls for developing rice genotypes that can be gown like dryland cereals. This dissertation aims to understand why so far rice cannot perform well under drier conditions via studying the basic anatomical, morphological and physiological mechanisms that determine the comparative adaptability of rice and wheat (Triticum aestivum) to water deficit.First, leaf anatomical and morphological attributes that affect leaf photosynthesis (An) and transpiration efficiency (TE) were investigated, using six representative rice genotypes and two wheat genotypes grown under long-term water deficit. Variations in An and TE were well explained by the CO2 diffusion components, i.e. stomatal conductance (gs) and mesophyll conductance (gm). Genotypic variation in gs among rice genotypes resulted from the differences in stomal density and size. Compared with wheat, the lower gm in rice was associated with its less optimized leaf mesophyll structures and anatomical properties.Secondly, anatomical traits that affect the acquisition and transport of water in root and shoot were examined at two developmental stages of three rice and two wheat genotypes. Rice roots possess extensive aerenchym but much smaller xylem vessels than wheat roots, while the xylem area in stem and leaf was higher in rice than in wheat. Compared with wheat, water deficit clearly induced the apoplastic barriers for radial water flow in rice roots and strongly limited the root growth and lateral root proliferation in rice, whereas the shoot growth in rice was less affected by treatments. As a result, there was an imbalance between water acquisition and transpiration demand

In the wake of declining water availability for agricultural use that will severely disturb the cultivation of irrigated lowland rice (Oryza sativa), aerobic genotypes have been developed allowing rice to grow under drier conditions. However, canopy physiological and morphological characteristics associated with adaptation of aerobic rice to water-limited conditions have so far been understudied. Canopy architectural characters, light and nitrogen distribution parameters (i.e. the extinction coefficient for light, KL; and for nitrogen, KN; and their ratio KN:KL), plant growth and yield were examined in irrigated-lowland (cv. IR64) vs aerobic (cv. Apo) rice genotypes grown under three water regimes. Compared with cv. IR64, cv. Apo allocated less nitrogen to strongly shaded leaves, allowing the vertical nitrogen distribution to better acclimate to light distribution within the canopy. The KN:KL ratio increased with increasing water deficit, and cv. Apo (up to 49 % increase) had a higher increase than cv. IR64 (up to 24 % increase). This was attributed to the maintenance of erect leaves at the upper part of the canopy, allocation of less leaf area and less nitrogen to the shaded leaves under water deficit in cv. Apo. The observed differential response in the KN:KL ratio partly explained the difference in biomass gain and yield in response to water deficit between the two rice cultivars. We concluded that favourable above-ground architecture and canopy nitrogen profile relative to the light profile contributed greatly to the better performance of cv. Apo than cv. IR64 under dry conditions.

Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (g s) and mesophyll conductance (g m) and their anatomical determinants were evaluated in two cultivars from each of lowland, aerobic, and upland groups of Oryza sativa, one cultivar of O. glaberrima, and two cultivars of T. aestivum, under three water regimes. The TE of upland rice, O. glaberrima, and wheat was more responsive to the g m /g s ratio than that of lowland and aerobic rice. Overall, the explanatory power of the particular anatomical trait varied among species. Low stomatal density mostly explained the low g s in drought-tolerant rice, whereas rice genotypes with smaller stomata generally responded more strongly to drought. Compared with rice, wheat had a higher g m, which was associated with thicker mesophyll tissue, mesophyll and chloroplasts more exposed to intercellular spaces, and thinner cell walls. Upland rice, O. glaberrima, and wheat cultivars minimized the decrease in g m under drought by maintaining high ratios of chloroplasts to exposed mesophyll cell walls. Rice TE could be improved by increasing the g m /g s ratio via modifying anatomical traits.