Effect of water deficiency on relationships between metabolism,physiology,biomass,and yield of upland cotton(Gossypium hirsutum L.)

Drought is a common abiotic stress that considerably limits crop production. The objective of this study is to explore the influence of water deficiency on the yield, physiologic and metabolomic attributes in upland cotton cultivars（Gossypium hirsutum L）. Cotton cultivars, ＇Ishonch＇ and ＇Tashkent-6＇ were selected to study the relationships among their physiologic, metabolomic and yield attributes during water deficiency. Deficit irrigation was designed by modifying the traditional watering protocol to reduce water use. Results indicate that cotton cultivars respond differently to water deficit stress. Water deficit significantly influenced plant height, the number of internodes, and sympodial branches in both cultivars. However, yield components such as the number of bolls, boll seed, lint mass, and individual plant yield were significantly reduced only in ＇Tashkent-6＇. The leaf area decreased and the specific leaf weight increased in ＇Ishonch＇ under deficit irrigation conditions. However, ＇Tashkent-6＇ demonstrated significant water loss compared to ＇Ishonch＇, and both cultivars showed reduced transpiration rates. Untargeted metabolite profiles of leaves showed clear separation in ＇Ishonch＇, but not in ＇Tashkent-6＇ under deficit irrigation compared to full irrigation. The individual metabolites such as proline and galactinol showed strong association with yield under water deficit stress. Moreover, this study indicates that leaf area and transpiration intensity influence yield during water deficiency. In summary, the correlation among morpho-physiologic, metabolic, and yield components significantly varied between the two cultivars under water deficiency. The flowering stage was sensitive to water stress for both cultivars. The direct relationship between physiology, metabolism, and yield may be a useful selection criterion for determining candidate parents for cotton drought tolerance breeding.

Micro Evolutionary Processes and Adaptation

It would be well to note that in the absence of clear data about the formation of adaptation systems,or mechanisms of their occurrence,all that is recognized is the realization of the micro evolutionary processes.There is no well-defined connection between information exchange and formation

JA but not JA-Ile is the cell-nonautonomous signal activating JA mediated systemic defenses to herbivory in Nicotiana attenuata

The whole-plant activation of defense responses to wounding and herbivory requires systemic signaling in which jasmonates （JAs） play a pivotal role. To examine the nature of the slower cell-nonautonomous as compared to the rapid cell-autonomous signal in mediating systemic defenses in Nicotiana attenuata, reciprocal stem graftingexperiments were used with plants silenced for the JA biosynthetic gene ALLENE OXIDE CYCLASE （irAOC） or plants transformed to create JA sinks by ectopicalIy expressing Arabidopsis JA-O-methyltransferase （ovJMT）. JA-impaired irAOC plants were defective in the cell-nonautonomous signaling pathway but not in JA transport. Conversely, ovJMT plants abrogated the production of a graft-transmissible JA signal. Both genotypes displayed unaltered cell-autonomous signaling. Defense responses （17-hydroxygeranyllinalool diterpene glycosides, nicotine, and proteinase inhibitors） and metabolite profiles were differently induced in irAOC and ovJMT scions in response to graft-transmissible signals from elicited wild type stocks. The performance of Manduca sexta larvae on the scions of different graft combinations was consistent with the patterns of systemic defense metabolite elicitations. Taken together, we conclude that JA and possibly MeJA, but not JA-lle, either directly functions as a long-distance transmissible signal or indirectly interacts with long distance signal（s） to activate systemic defense responses.