RESUMEN
Plant responses to drought stress have been analyzed extensively to reveal complex regulatory gene networks, including the detection of water deficit signals, as well as the physiological, cellular, and molecular responses. Plants recognize water deficit conditions at their roots and transmit this signal to their shoots to synthesize abscisic acid (ABA) in their leaves. ABA is a key phytohormone that regulates physiological and molecular responses to drought stress, such as stomatal closure, gene expression, and the accumulation of osmoprotectants and stress proteins. ABA transporters function as the first step for propagating synthesized ABA. To prevent water loss, ABA influx in guard cells is detected by several protein kinases, such as SnRK2s and MAPKs that regulate stomatal closure. ABA mediates a wide variety of gene expression machineries with stress-responsive transcription factors, including DREBs and AREBs, to acquire drought stress resistance in whole tissues. In this chapter, we summarize recent advances in drought stress signaling, focusing on gene networks in cellular and intercellular stress responses and drought resistance.
Asunto(s)
Aclimatación , Sequías , Regulación de la Expresión Génica de las Plantas , Redes Reguladoras de Genes , Genes de Plantas , Proteínas de Plantas/genética , Plantas/genética , Ácido Abscísico/metabolismo , Deshidratación/genética , Estado de Hidratación del Organismo/genética , Desarrollo de la Planta , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Transducción de Señal , Agua/metabolismoRESUMEN
BACKGROUND: The well-known insertion/deletion polymorphism (rs4646994) of the angiotensin-converting enzyme (ACE) gene has been previously associated with obesity, blood flow, muscular strength, and ACE enzyme activity. Despite the relevant role of ACE in homeostasis, few data are currently available on the relationship between rs4646994 and hydration status. Thus, we tested the association between the ACE Ins/Del polymorphism, body composition, and hydration status in a young Italian population. METHODS: A total of 306 healthy children and adolescents who regularly practice sports were recruited. Anthropometric, bioimpedentiometric parameters, and urine samples were collected, while ACE rs4646994 genotyping was performed on DNA from buccal swabs. General linear models were used for association testing. RESULTS: The ACE Ins/Del polymorphism was associated with body composition. Ins/Ins individuals had higher phase angle (PhA) and body cellular mass index (BCMI) values. A significant influence of the ACE rs4646994 according to hydration status on body composition was also identified. In particular, Ins/Ins individuals displayed higher PhA and BCMI values only if norm-hydrated, while they showed values similar to Del carriers if dehydrated. CONCLUSION: Our results confirm the relationship between the ACE Ins/Del polymorphism and body composition and suggest a role for hydration status in modulating this relationship. These interesting preliminary results warrant further investigation to disentangle the genetic role of ACE on hydration homeostasis.